RNA INTERFERENCE MEDIATED INHIBITION OF STEAROYL-CoA DESATURASE (SCD) GENE EXPRESSION USING SHORT INTERFERING NUCELIC ACID (siNA)

ABSTRACT

This invention relates to compounds, compositions, and methods useful for modulating Stearoyl-CoA desaturase (SCD) gene expression using short interfering nucleic acid (siNA) molecules. This invention also relates to compounds, compositions, and methods useful for modulating the expression and activity of other genes involved in pathways of Stearoyl-CoA desaturase (SCD) gene expression and/or activity by RNA interference (RNAi) using small nucleic acid molecules. In particular, the instant invention features small nucleic acid molecules, such as short interfering nucleic acid (siNA), short interfering RNA (siRNA), double-stranded RNA (dsRNA), micro-RNA (miRNA), and short hairpin RNA (shRNA) molecules and methods used to modulate the expression of Stearoyl-CoA desaturase (SCD) genes.

This application is a continuation of U.S. patent application Ser. No. 10/923,451, filed Aug. 20, 2004, which is a continuation-in-part of International Patent Application No. PCT/US03/04317, filed Feb. 13, 2003, which claims the benefit of U.S. Provisional Application No. 60/412,304, filed Sep. 20, 2002 and parent U.S. patent application Ser. No. 10/923,451 is also a continuation-in-part of International Patent Application No. PCT/US04/16390, filed May 24, 2004, which is a continuation-in-part of U.S. patent application Ser. No. 10/826,966, filed Apr. 16, 2004, which is continuation-in-part of U.S. patent application Ser. No. 10/757,803, filed Jan. 14, 2004, which is a continuation-in-part of U.S. patent application Ser. No. 10/720,448, filed Nov. 24, 2003, which is a continuation-in-part of U.S. patent application Ser. No. 10/693,059, filed Oct. 23, 2003, which is a continuation-in-part of U.S. patent application Ser. No. 10/444,853, filed May 23, 2003, which is a continuation-in-part of International Patent Application No. PCT/US03/05346, filed Feb. 20, 2003, and a continuation-in-part of International Patent Application No. PCT/US03/05028, filed Feb. 20, 2003, both of which claim the benefit of U.S. Provisional Application No. 60/358,580 filed Feb. 20, 2002, U.S. Provisional Application No. 60/363,124 filed Mar. 11, 2002, U.S. Provisional Application No. 60/386,782 filed Jun. 6, 2002, U.S. Provisional Application No. 60/406,784 filed Aug. 29, 2002, U.S. Provisional Application No. 60/408,378 filed Sep. 5, 2002, U.S. Provisional Application No. 60/409,293 filed Sep. 9, 2002, and U.S. Provisional Application No. 60/440,129 filed Jan. 15, 2003. The instant application claims the benefit of all the listed applications, which are hereby incorporated by reference herein in their entireties, including the drawings.

SEQUENCE LISTING

The sequence listing submitted via EFS, in compliance with 37 CFR §1.52(e)(5), is incorporated herein by reference. The sequence listing text file submitted via EFS contains the file “SequenceListing42USCNT”, created on Aug. 15, 2008, which is 266,422 bytes in size.

FIELD OF THE INVENTION

The present invention relates to compounds, compositions, and methods for the study, diagnosis, and treatment of traits, diseases and conditions that respond to the modulation of Stearoyl-CoA desaturase (SCD) gene expression and/or activity. The present invention is also directed to compounds, compositions, and methods relating to traits, diseases and conditions that respond to the modulation of expression and/or activity of genes involved in Stearoyl-CoA desaturase (SCD) gene expression pathways or other cellular processes that mediate the maintenance or development of such traits, diseases and conditions. Specifically, the invention relates to small nucleic acid molecules, such as short interfering nucleic acid (siNA), short interfering RNA (siRNA), double-stranded RNA (dsRNA), micro-RNA (miRNA), and short hairpin RNA (shRNA) molecules capable of mediating RNA interference (RNAi) against Stearoyl-CoA desaturase (SCD) gene expression. Such small nucleic acid molecules are useful, for example, in providing compositions for treatment of traits, diseases and conditions that can respond to modulation of SCD expression in a subject, such as diabetes (type I and/or type II), atherosclerosis, cancer, obesity, and viral infection.

BACKGROUND OF THE INVENTION

The following is a discussion of relevant art pertaining to RNAi. The discussion is provided only for understanding of the invention that follows. The summary is not an admission that any of the work described below is prior art to the claimed invention.

RNA interference refers to the process of sequence-specific post-transcriptional gene silencing in animals mediated by short interfering RNAs (siRNAs) (Zamore et al., 2000, Cell, 101, 25-33; Fire et al., 1998, Nature, 391, 806; Hamilton et al., 1999, Science, 286, 950-951; Lin et al., 1999, Nature, 402, 128-129; Sharp, 1999, Genes & Dev., 13:139-141; and Strauss, 1999, Science, 286, 886). The corresponding process in plants (Heifetz et al., International PCT Publication No. WO 99/61631) is commonly referred to as post-transcriptional gene silencing or RNA silencing and is also referred to as quelling in fungi. The process of post-transcriptional gene silencing is thought to be an evolutionarily-conserved cellular defense mechanism used to prevent the expression of foreign genes and is commonly shared by diverse flora and phyla (Fire et al., 1999, Trends Genet., 15, 358). Such protection from foreign gene expression may have evolved in response to the production of double-stranded RNAs (dsRNAs) derived from viral infection or from the random integration of transposon elements into a host genome via a cellular response that specifically destroys homologous single-stranded RNA or viral genomic RNA. The presence of dsRNA in cells triggers the RNAi response through a mechanism that has yet to be fully characterized. This mechanism appears to be different from other known mechanisms involving double-stranded RNA-specific ribonucleases, such as the interferon response that results from dsRNA-mediated activation of protein kinase PKR and 2′,5′-oligoadenylate synthetase resulting in non-specific cleavage of mRNA by ribonuclease L (see for example U.S. Pat. Nos. 6,107,094; 5,898,031; Clemens et al., 1997, J. Interferon & Cytokine Res., 17, 503-524; Adah et al., 2001, Curr. Med. Chem., 8, 1189).

The presence of long dsRNAs in cells stimulates the activity of a ribonuclease III enzyme referred to as dicer (Bass, 2000, Cell, 101, 235; Zamore et al., 2000, Cell, 101, 25-33; Hammond et al., 2000, Nature, 404, 293). Dicer is involved in the processing of the dsRNA into short pieces of dsRNA known as short interfering RNAs (siRNAs) (Zamore et al., 2000, Cell, 101, 25-33; Bass, 2000, Cell, 101, 235; Berstein et al., 2001, Nature, 409, 363). Short interfering RNAs derived from dicer activity are typically about 21 to about 23 nucleotides in length and comprise about 19 base pair duplexes (Zamore et al., 2000, Cell, 101, 25-33; Elbashir et al., 2001, Genes Dev., 15, 188). Dicer has also been implicated in the excision of 21- and 22-nucleotide small temporal RNAs (stRNAs) from precursor RNA of conserved structure that are implicated in translational control (Hutvagner et al., 2001, Science, 293, 834). The RNAi response also features an endonuclease complex, commonly referred to as an RNA-induced silencing complex (RISC), which mediates cleavage of single-stranded RNA having sequence complementary to the antisense strand of the siRNA duplex. Cleavage of the target RNA takes place in the middle of the region complementary to the antisense strand of the siRNA duplex (Elbashir et al., 2001, Genes Dev., 15, 188).

RNAi has been studied in a variety of systems. Fire et al., 1998, Nature, 391, 806, were the first to observe RNAi in C. elegans. Bahramian and Zarbl, 1999, Molecular and Cellular Biology, 19, 274-283 and Wianny and Goetz, 1999, Nature Cell Biol., 2, 70, describe RNAi mediated by dsRNA in mammalian systems. Hammond et al., 2000, Nature, 404, 293, describe RNAi in Drosophila cells transfected with dsRNA. Elbashir et al., 2001, Nature, 411, 494 and Tuschl et al., International PCT Publication No. WO 01/75164, describe RNAi induced by introduction of duplexes of synthetic 21-nucleotide RNAs in cultured mammalian cells including human embryonic kidney and HeLa cells. Recent work in Drosophila embryonic lysates (Elbashir et al., 2001, EMBO J., 20, 6877 and Tuschl et al., International PCT Publication No. WO 01/75164) has revealed certain requirements for siRNA length, structure, chemical composition, and sequence that are essential to mediate efficient RNAi activity. These studies have shown that 21-nucleotide siRNA duplexes are most active when containing 3′-terminal dinucleotide overhangs. Furthermore, complete substitution of one or both siRNA strands with 2′-deoxy (2′-H) or 2′-O-methyl nucleotides abolishes RNAi activity, whereas substitution of the 3′-terminal siRNA overhang nucleotides with 2′-deoxy nucleotides (2′-H) was shown to be tolerated. Single mismatch sequences in the center of the siRNA duplex were also shown to abolish RNAi activity. In addition, these studies also indicate that the position of the cleavage site in the target RNA is defined by the 5′-end of the siRNA guide sequence rather than the 3′-end of the guide sequence (Elbashir et al., 2001, EMBO J., 20, 6877). Other studies have indicated that a 5′-phosphate on the target-complementary strand of an siRNA duplex is required for siRNA activity and that ATP is utilized to maintain the 5′-phosphate moiety on the siRNA (Nykanen et al., 2001, Cell, 107, 309).

Studies have shown that replacing the 3′-terminal nucleotide overhanging segments of a 21-mer siRNA duplex having two-nucleotide 3′-overhangs with deoxyribonucleotides does not have an adverse effect on RNAi activity. Replacing up to four nucleotides on each end of the siRNA with deoxyribonucleotides has been reported to be well tolerated, whereas complete substitution with deoxyribonucleotides results in no RNAi activity (Elbashir et al., 2001, EMBO J., 20, 6877 and Tuschl et al., International PCT Publication No. WO 01/75164). In addition, Elbashir et al., supra, also report that substitution of siRNA with 2′-O-methyl nucleotides completely abolishes RNAi activity. Li et al., International PCT Publication No. WO 00/44914, and Beach et al., International PCT Publication No. WO 01/68836 preliminarily suggest that siRNA may include modifications to either the phosphate-sugar backbone or the nucleoside to include at least one of a nitrogen or sulfur heteroatom, however, neither application postulates to what extent such modifications would be tolerated in siRNA molecules, nor provides any further guidance or examples of such modified siRNA. Kreutzer et al., Canadian Patent Application No. 2,359,180, also describe certain chemical modifications for use in dsRNA constructs in order to counteract activation of double-stranded RNA-dependent protein kinase PKR, specifically 2′-amino or 2′-O-methyl nucleotides, and nucleotides containing a 2′-O or 4′-C methylene bridge. However, Kreutzer et al. similarly fails to provide examples or guidance as to what extent these modifications would be tolerated in dsRNA molecules.

Parrish et al., 2000, Molecular Cell, 6, 1077-1087, tested certain chemical modifications targeting the unc-22 gene in C. elegans using long (>25 nt) siRNA transcripts. The authors describe the introduction of thiophosphate residues into these siRNA transcripts by incorporating thiophosphate nucleotide analogs with T7 and T3 RNA polymerase and observed that RNAs with two phosphorothioate modified bases also had substantial decreases in effectiveness as RNAi. Further, Parrish et al. reported that phosphorothioate modification of more than two residues greatly destabilized the RNAs in vitro such that interference activities could not be assayed. Id. at 1081. The authors also tested certain modifications at the 2′-position of the nucleotide sugar in the long siRNA transcripts and found that substituting deoxynucleotides for ribonucleotides produced a substantial decrease in interference activity, especially in the case of Uridine to Thymidine and/or Cytidine to deoxy-Cytidine substitutions. Id. In addition, the authors tested certain base modifications, including substituting, in sense and antisense strands of the siRNA, 4-thiouracil, 5-bromouracil, 5-iodouracil, and 3-(aminoallyl)uracil for uracil, and inosine for guanosine. Whereas 4-thiouracil and 5-bromouracil substitution appeared to be tolerated, Parrish reported that inosine produced a substantial decrease in interference activity when incorporated in either strand. Parrish also reported that incorporation of 5-iodouracil and 3-(aminoallyl)uracil in the antisense strand resulted in a substantial decrease in RNAi activity as well.

The use of longer dsRNA has been described. For example, Beach et al., International PCT Publication No. WO 01/68836, describes specific methods for attenuating gene expression using endogenously-derived dsRNA. Tuschl et al., International PCT Publication No. WO 01/75164, describe a Drosophila in vitro RNAi system and the use of specific siRNA molecules for certain functional genomic and certain therapeutic applications; although Tuschl, 2001, Chem. Biochem., 2, 239-245, doubts that RNAi can be used to cure genetic diseases or viral infection due to the danger of activating interferon response. Li et al., International PCT Publication No. WO 00/44914, describe the use of specific long (141 bp488 bp) enzymatically synthesized or vector expressed dsRNAs for attenuating the expression of certain target genes. Zernicka-Goetz et al., International PCT Publication No. WO 01/36646, describe certain methods for inhibiting the expression of particular genes in mammalian cells using certain long (550 bp-714 bp), enzymatically synthesized or vector expressed dsRNA molecules. Fire et al., International PCT Publication No. WO 99/32619, describe particular methods for introducing certain long dsRNA molecules into cells for use in inhibiting gene expression in nematodes. Plaetinck et al., International PCT Publication No. WO 00/01846, describe certain methods for identifying specific genes responsible for conferring a particular phenotype in a cell using specific long dsRNA molecules. Mello et al., International PCT Publication No. WO 01/29058, describe the identification of specific genes involved in dsRNA-mediated RNAi. Pachuck et al., International PCT Publication No. WO 00/63364, describe certain long (at least 200 nucleotide) dsRNA constructs. Deschamps Depaillette et al., International PCT Publication No. WO 99/07409, describe specific compositions consisting of particular dsRNA molecules combined with certain anti-viral agents. Waterhouse et al., International PCT Publication No. 99/53050 and 1998, PNAS, 95, 13959-13964, describe certain methods for decreasing the phenotypic expression of a nucleic acid in plant cells using certain dsRNAs. Driscoll et al., International PCT Publication No. WO 01/49844, describe specific DNA expression constructs for use in facilitating gene silencing in targeted organisms.

Others have reported on various RNAi and gene-silencing systems. For example, Parrish et al., 2000, Molecular Cell, 6, 1077-1087, describe specific chemically modified dsRNA constructs targeting the unc-22 gene of C. elegans. Grossniklaus, International PCT Publication No. WO 01/38551, describes certain methods for regulating polycomb gene expression in plants using certain dsRNAs. Churikov et al., International PCT Publication No. WO 01/42443, describe certain methods for modifying genetic characteristics of an organism using certain dsRNAs. Cogoni et al, International PCT Publication No. WO 01/53475, describe certain methods for isolating a Neurospora silencing gene and uses thereof. Reed et al., International PCT Publication No. WO 01/68836, describe certain methods for gene silencing in plants. Honer et al., International PCT Publication No. WO 01/70944, describe certain methods of drug screening using transgenic nematodes as Parkinson's Disease models using certain dsRNAs. Deak et al., International PCT Publication No. WO 01/72774, describe certain Drosophila-derived gene products that may be related to RNAi in Drosophila. Arndt et al., International PCT Publication No. WO 01/92513 describe certain methods for mediating gene suppression by using factors that enhance RNAi. Tuschl et al., International PCT Publication No. WO 02/44321, describe certain synthetic siRNA constructs. Pachuk et al., International PCT Publication No. WO 00/63364, and Satishchandran et al., International PCT Publication No. WO 01/04313, describe certain methods and compositions for inhibiting the function of certain polynucleotide sequences using certain long (over 250 bp), vector expressed dsRNAs. Echeverri et al., International PCT Publication No. WO 02/38805, describe certain C. elegans genes identified via RNAi. Kreutzer et al., International PCT Publications Nos. WO 02/055692, WO 02/055693, and EP 1144623 B1 describes certain methods for inhibiting gene expression using dsRNA. Graham et al., International PCT Publications Nos. WO 99/49029 and WO 01/70949, and AU 4037501 describe certain vector expressed siRNA molecules. Fire et al., U.S. Pat. No. 6,506,559, describe certain methods for inhibiting gene expression in vitro using certain long dsRNA (299 bp-1033 bp) constructs that mediate RNAi. Martinez et al., 2002, Cell, 110, 563-574, describe certain single-stranded siRNA constructs, including certain 5′-phosphorylated single-stranded siRNAs that mediate RNA interference in HeLa cells. Harborth et al., 2003, Antisense & Nucleic Acid Drug Development, 13, 83-105, describe certain chemically and structurally modified siRNA molecules. Chiu and Rana, 2003, RNA, 9, 1034-1048, describe certain chemically and structurally modified siRNA molecules. Woolf et al., International PCT Publication Nos. WO 03/064626 and WO 03/064625 describe certain chemically modified dsRNA constructs.

Brownlie et al., International PCT Publication No. WO 01/62954, describe methods and compositions using stearoyl-CoA desaturase to identify certain triglyceride reducing therapeutic agents.

SUMMARY OF THE INVENTION

This invention relates to compounds, compositions, and methods useful for modulating Stearoyl-CoA desaturase (SCD) gene expression using short interfering nucleic acid (siNA) molecules. This invention also relates to compounds, compositions, and methods useful for modulating the expression and activity of other genes involved in pathways of SCD gene expression and/or activity by RNA interference (RNAi) using small nucleic acid molecules. In particular, the instant invention features small nucleic acid molecules, such as short interfering nucleic acid (siNA), short interfering RNA (siRNA), double-stranded RNA (dsRNA), micro-RNA (miRNA), and short hairpin RNA (shRNA) molecules and methods used to modulate the expression of SCD genes.

An siNA of the invention can be unmodified or chemically modified. An siNA of the instant invention can be chemically synthesized, expressed from a vector or enzymatically synthesized. The instant invention also features various chemically modified synthetic short interfering nucleic acid (siNA) molecules capable of modulating SCD gene expression or activity in cells by RNA interference (RNAi). The use of chemically modified siNA improves various properties of native siNA molecules through increased resistance to nuclease degradation in vivo and/or through improved cellular uptake. Further, contrary to earlier published studies, siNA having multiple chemical modifications retains its RNAi activity. The siNA molecules of the instant invention provide useful reagents and methods for a variety of therapeutic, veterinary, diagnostic, target validation, genomic discovery, genetic engineering, and pharmacogenomic applications.

In one embodiment, the invention features one or more siNA molecules and methods that independently or in combination modulate the expression of SCD genes encoding proteins, such as proteins comprising SCD associated with the maintenance and/or development of diabetes (type I and/or type II), atherosclerosis, cancer, obesity, and viral infection, such as genes encoding sequences comprising those sequences referred to by GenBank Accession Nos. shown in Table I, referred to herein generally as Stearoyl-CoA desaturase or SCD. The description below of the various aspects and embodiments of the invention is provided with reference to exemplary Stearoyl-CoA desaturase gene referred to herein as SCD. However, the various aspects and embodiments are also directed to other SCD genes, such as homolog genes and transcript variants, and polymorphisms (e.g., single nucleotide polymorphism, (SNPs)) associated with certain SCD genes. As such, the various aspects and embodiments are also directed to other genes that are involved in SCD mediated pathways of signal transduction or gene expression that are involved, for example, in the maintenance or development of diseases, traits, or conditions described herein. These, additional genes can be analyzed for target sites using the methods described for SCD genes herein. Thus, the modulation of other genes and the effects of such modulation of the other genes can be performed, determined, and measured as described herein.

In one embodiment, the invention features a double-stranded short interfering nucleic acid (siNA) molecule that down-regulates expression of a SCD gene, wherein said siNA molecule comprises about 15 to about 28 base pairs.

In one embodiment, the invention features a double-stranded short interfering nucleic acid (siNA) molecule that directs cleavage of a SCD RNA via RNA interference (RNAi), wherein the double-stranded siNA molecule comprises a first and a second strand, each strand of the siNA molecule is about 18 to about 28 nucleotides in length, the first strand of the siNA molecule comprises nucleotide sequence having sufficient complementarity to the SCD RNA for the siNA molecule to direct cleavage of the SCD RNA via RNA interference, and the second strand of said siNA molecule comprises nucleotide sequence that is complementary to the first strand.

In one embodiment, the invention features a double-stranded short interfering nucleic acid (siNA) molecule that directs cleavage of a SCD RNA via RNA interference (RNAi), wherein the double-stranded siNA molecule comprises a first and a second strand, each strand of the siNA molecule is about 18 to about 23 nucleotides in length, the first strand of the siNA molecule comprises nucleotide sequence having sufficient complementarity to the SCD RNA for the siNA molecule to direct cleavage of the SCD RNA via RNA interference, and the second strand of said siNA molecule comprises nucleotide sequence that is complementary to the first strand.

In one embodiment, the invention features a chemically synthesized double-stranded short interfering nucleic acid (siNA) molecule that directs cleavage of a SCD RNA via RNA interference (RNAi), wherein each strand of the siNA molecule is about 18 to about 28 nucleotides in length; and one strand of the siNA molecule comprises nucleotide sequence having sufficient complementarity to the SCD RNA for the siNA molecule to direct cleavage of the SCD RNA via RNA interference.

In one embodiment, the invention features a chemically synthesized double-stranded short interfering nucleic acid (siNA) molecule that directs cleavage of a SCD RNA via RNA interference (RNAi), wherein each strand of the siNA molecule is about 18 to about 23 nucleotides in length; and one strand of the siNA molecule comprises nucleotide sequence having sufficient complementarity to the SCD RNA for the siNA molecule to direct cleavage of the SCD RNA via RNA interference.

In one embodiment, the invention features an siNA molecule that down-regulates expression of a SCD gene, for example, wherein the SCD gene comprises SCD encoding sequence. In one embodiment, the invention features an siNA molecule that down-regulates expression of a SCD gene, for example, wherein the SCD gene comprises SCD non-coding sequence or regulatory elements involved in SCD gene expression.

In one embodiment, an siNA of the invention is used to inhibit the expression of SCD genes or a SCD gene family, wherein the genes or gene family sequences share sequence homology. Such homologous sequences can be identified as is known in the art, for example using sequence alignments. siNA molecules can be designed to target such homologous sequences, for example using perfectly complementary sequences or by incorporating non-canonical base pairs, for example mismatches and/or wobble base pairs that can provide additional target sequences. In instances where mismatches are identified, non-canonical base pairs (for example, mismatches and/or wobble bases) can be used to generate siNA molecules that target more than one gene sequence. In a non-limiting example, non-canonical base pairs such as UU and CC base pairs are used to generate siNA molecules that are capable of targeting sequences for differing SCD targets that share sequence homology. As such, one advantage of using siNAs of the invention is that a single siNA can be designed to include nucleic acid sequence that is complementary to the nucleotide sequence that is conserved between the homologous genes. In this approach, a single siNA can be used to inhibit expression of more than one gene instead of using more than one siNA molecule to target the different genes.

In one embodiment, the invention features an siNA molecule having RNAi activity against SCD RNA, wherein the siNA molecule comprises a sequence complementary to any RNA having SCD encoding sequence, such as those sequences having GenBank Accession Nos. shown in Table I. In another embodiment, the invention features an siNA molecule having RNAi activity against SCD RNA, wherein the siNA molecule comprises a sequence complementary to an RNA having variant SCD encoding sequence, for example other mutant SCD genes not shown in Table I but known in the art to be associated with the maintenance and/or development of diabetes (type I and/or type II), atherosclerosis, cancer, obesity, and viral infection. Chemical modifications as shown in Tables III and IV or otherwise described herein can be applied to any siNA construct of the invention. In another embodiment, an siNA molecule of the invention includes a nucleotide sequence that can interact with nucleotide sequence of a SCD gene and thereby mediate silencing of SCD gene expression, for example, wherein the siNA mediates regulation of SCD gene expression by cellular processes that modulate the chromatin structure or methylation patterns of the SCD gene and prevent transcription of the SCD gene.

In one embodiment, siNA molecules of the invention are used to down regulate or inhibit the expression of SCD proteins arising from SCD haplotype polymorphisms that are associated with a disease or condition, (e.g., diabetes (type I and/or type II), atherosclerosis, cancer, obesity, and viral infection). Analysis of SCD genes, or SCD protein or RNA levels can be used to identify subjects with such polymorphisms or those subjects who are at risk of developing traits, conditions, or diseases described herein. These subjects are amenable to treatment, for example, treatment with siNA molecules of the invention and any other composition useful in-treating diseases related to SCD gene expression. As such, analysis of SCD protein or RNA levels can be used to determine treatment type and the course of therapy in treating a subject. Monitoring of SCD protein or RNA levels can be used to predict treatment outcome and to determine the efficacy of compounds and compositions that modulate the level and/or activity of certain SCD proteins associated with a trait, condition, or disease.

In one embodiment of the invention an siNA molecule comprises an antisense strand comprising a nucleotide sequence that is complementary to a nucleotide sequence or a portion thereof encoding a SCD protein. The siNA further comprises a sense strand, wherein said sense strand comprises a nucleotide sequence of a SCD gene or a portion thereof.

In another embodiment, an siNA molecule comprises an antisense region comprising a nucleotide sequence that is complementary to a nucleotide sequence encoding a SCD protein or a portion thereof. The siNA molecule further comprises a sense region, wherein said sense region comprises a nucleotide sequence of a SCD gene or a portion thereof.

In another embodiment, the invention features an siNA molecule comprising a nucleotide sequence in the antisense region of the siNA molecule that is complementary to a nucleotide sequence or portion of sequence of a SCD gene. In another embodiment, the invention features an siNA molecule comprising a region, for example, the antisense region of the siNA construct, complementary to a sequence comprising a SCD gene sequence or a portion thereof.

In one embodiment, the antisense region of SCD siNA constructs comprises a sequence complementary to sequence having any of SEQ ID NOs. 1-290 or 581-596. In one embodiment, the antisense region of SCD constructs comprises sequence having any of SEQ ID NOs. 291-580, 605-612, 621-628, 637-644, 653-660, 669-692, 701-708, 717-724, 733-740, 749-756, 765-788, 790, 792, 794, 797, 799, 801, 803, or 806. In another embodiment, the sense region of SCD constructs comprises sequence having any of SEQ ID NOs. 1-290, 581-604, 613-620, 629-636, 645-652, 661-668, 693-700, 709-716, 725-732, 741-748, 757-764, 789, 791, 793, 795, 796, 798, 800, 802, 804, or 805.

In one embodiment, an siNA molecule of the invention comprises any of SEQ ID NOs. 1-806. The sequences shown in SEQ ID NOs: 1-806 are not limiting. An siNA molecule of the invention can comprise any contiguous SCD sequence (e.g., about 15 to about 25 or more, or about 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, or 25 or more contiguous SCD nucleotides).

In yet another embodiment, the invention features an siNA molecule comprising a sequence, for example, the antisense sequence of the siNA construct, complementary to a sequence or portion of sequence comprising sequence represented by GenBank Accession Nos. shown in Table I. Chemical modifications in Tables III and IV and described herein can be applied to any siNA construct of the invention.

In one embodiment of the invention an siNA molecule comprises an antisense strand having about 15 to about 30 (e.g., about 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, or 30) nucleotides, wherein the antisense strand is complementary to a RNA sequence or a portion thereof encoding a SCD protein, and wherein said siNA further comprises a sense strand having about 15 to about 30 (e.g., about 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, or 30) nucleotides, and wherein said sense strand and said antisense strand are distinct nucleotide sequences where at least about 15 nucleotides in each strand are complementary to the other strand.

In another embodiment of the invention an siNA molecule of the invention comprises an antisense region having about 15 to about 30 (e.g., about 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, or 30) nucleotides, wherein the antisense region is complementary to a RNA sequence encoding a SCD protein, and wherein said siNA further comprises a sense region having about 15 to about 30 (e.g., about 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, or 30) nucleotides, wherein said sense region and said antisense region are comprised in a linear molecule where the sense region comprises at least about 15 nucleotides that are complementary to the antisense region.

In one embodiment, an siNA molecule of the invention has RNAi activity that modulates expression of RNA encoded by a SCD gene. Because SCD genes can share some degree of sequence homology with each other, siNA molecules can be designed to target a class of SCD genes or alternately specific SCD genes (e.g., polymorphic variants) by selecting sequences that are either shared amongst different SCD targets or alternatively that are unique for a specific SCD target. Therefore, in one embodiment, the siNA molecule can be designed to target conserved regions of SCD RNA sequences having homology among several SCD gene variants so as to target a class of SCD genes with one siNA molecule. Accordingly, in one embodiment, the siNA molecule of the invention modulates the expression of one or both SCD alleles in a subject. In another embodiment, the siNA molecule can be designed to target a sequence that is unique to a specific SCD RNA sequence (e.g., a single SCD allele or SCD single nucleotide polymorphism (SNP)) due to the high degree of specificity that the siNA molecule requires to mediate RNAi activity.

In one embodiment, nucleic acid molecules of the invention that act as mediators of the RNA interference gene silencing response are double-stranded nucleic acid molecules. In another embodiment, the siNA molecules of the invention consist of duplex nucleic acid molecules containing about 15 to about 30 base pairs between oligonucleotides comprising about 15 to about 30 (e.g., about 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, or 30) nucleotides. In yet another embodiment, siNA molecules of the invention comprise duplex nucleic acid molecules with overhanging ends of about 1 to about 3 (e.g., about 1, 2, or 3) nucleotides, for example, about 21-nucleotide duplexes with about 19 base pairs and 3′-terminal mononucleotide, dinucleotide, or trinucleotide overhangs. In yet another embodiment, siNA molecules of the invention comprise duplex nucleic acid molecules with blunt ends, where both ends are blunt, or alternatively, where one of the ends is blunt.

In one embodiment, the invention features one or more chemically modified siNA constructs having specificity for SCD expressing nucleic acid molecules, such as RNA encoding a SCD protein. In one embodiment, the invention features a RNA based siNA molecule (e.g., an siNA comprising 2′-OH nucleotides) having specificity for SCD expressing nucleic acid molecules that includes one or more chemical modifications described herein. Non-limiting examples of such chemical modifications include without limitation phosphorothioate internucleotide linkages, 2′-deoxyribonucleotides, 2′-O-methyl ribonucleotides, 2′-deoxy-2′-fluoro ribonucleotides, “universal base” nucleotides, “acyclic” nucleotides, 5-C-methyl nucleotides, and terminal glyceryl and/or inverted deoxy abasic residue incorporation. These chemical modifications, when used in various siNA constructs, (e.g., RNA based siNA constructs), are shown to preserve RNAi activity in cells while at the same time, dramatically increasing the serum stability of these compounds. Furthermore, contrary to the data published by Parrish et al., supra, applicant demonstrates that multiple (greater than one) phosphorothioate substitutions are well-tolerated and confer substantial increases in serum stability for modified siNA constructs.

In one embodiment, an siNA molecule of the invention comprises modified nucleotides while maintaining the ability to mediate RNAi. The modified nucleotides can be used to improve in vitro or in vivo characteristics such as stability, activity, and/or bioavailability. For example, an siNA molecule of the invention can comprise modified nucleotides as a percentage of the total number of nucleotides present in the siNA molecule. As such, an siNA molecule of the invention can generally comprise about 5% to about 100% modified nucleotides (e.g., about 5%, 10%, 15%, 20%, 25%, 30%, 35%, 40%, 45%, 50%, 55%, 60%, 65%, 70%, 75%, 80%, 85%, 90%, 95% or 100% modified nucleotides). The actual percentage of modified nucleotides present in a given siNA molecule will depend on the total number of nucleotides present in the siNA. If the siNA molecule is single-stranded, the percent modification can be based upon the total number of nucleotides present in the single-stranded siNA molecules. Likewise, if the siNA molecule is double-stranded, the percent modification can be based upon the total number of nucleotides present in the sense strand, antisense strand, or both the sense and antisense strands.

One aspect of the invention features a double-stranded short interfering nucleic acid (siNA) molecule that down-regulates expression of a SCD gene. In one embodiment, the double-stranded siNA molecule comprises one or more chemical modifications and each strand of the double-stranded siNA is about 21 nucleotides long. In one embodiment, the double-stranded siNA molecule does not contain any ribonucleotides. In another embodiment, the double-stranded siNA molecule comprises one or more ribonucleotides. In one embodiment, each strand of the double-stranded siNA molecule independently comprises about 15 to about 30 (e.g., about 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, or 30) nucleotides, wherein each strand comprises about 15 to about 30 (e.g., about 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, or 30) nucleotides that are complementary to the nucleotides of the other strand. In one embodiment, one of the strands of the double-stranded siNA molecule comprises a nucleotide sequence that is complementary to a nucleotide sequence or a portion thereof of the SCD gene, and the second strand of the double-stranded siNA molecule comprises a nucleotide sequence substantially similar to the nucleotide sequence of the SCD gene or a portion thereof.

In another embodiment, the invention features a double-stranded short interfering nucleic acid (siNA) molecule that down-regulates expression of a SCD gene comprising an antisense region, wherein the antisense region comprises a nucleotide sequence that is complementary to a nucleotide sequence of the SCD gene or a portion thereof, and a sense region, wherein the sense region comprises a nucleotide sequence substantially similar to the nucleotide sequence of the SCD gene or a portion thereof. In one embodiment, the antisense region and the sense region independently comprise about 15 to about 30 (e.g. about 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, or 30) nucleotides, wherein the antisense region comprises about 15 to about 30 (e.g. about 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, or 30) nucleotides that are complementary to nucleotides of the sense region.

In another embodiment, the invention features a double-stranded short interfering nucleic acid (siNA) molecule that down-regulates expression of a SCD gene comprising a sense region and an antisense region, wherein the antisense region comprises a nucleotide sequence that is complementary to a nucleotide sequence of RNA encoded by the SCD gene or a portion thereof and the sense region comprises a nucleotide sequence that is complementary to the antisense region.

In one embodiment, an siNA molecule of the invention comprises blunt ends, i.e., ends that do not include any overhanging nucleotides. For example, an siNA molecule comprising modifications described herein (e.g., comprising nucleotides having Formulae I-VII or siNA constructs comprising “Stab 00”-“Stab 32” (Table IV) or any combination thereof (see Table IV)) and/or any length described herein can comprise blunt ends or ends with no overhanging nucleotides.

In one embodiment, any siNA molecule of the invention can comprise one or more blunt ends, i.e. where a blunt end does not have any overhanging nucleotides. In one embodiment, the blunt ended siNA molecule has a number of base pairs equal to the number of nucleotides present in each strand of the siNA molecule. In another embodiment, the siNA molecule comprises one blunt end, for example wherein the 5′-end of the antisense strand and the 3′-end of the sense strand do not have any overhanging nucleotides. In another example, the siNA molecule comprises one blunt end, for example wherein the 3′-end of the antisense strand and the 5′-end of the sense strand do not have any overhanging nucleotides. In another example, an siNA molecule comprises two blunt ends, for example wherein the 3′-end of the antisense strand and the 5′-end of the sense strand as well as the 5′-end of the antisense strand and 3′-end of the sense strand do not have any overhanging nucleotides. A blunt ended siNA molecule can comprise, for example, from about 15 to about 30 nucleotides (e.g., about 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, or 30 nucleotides). Other nucleotides present in a blunt ended siNA molecule can comprise, for example, mismatches, bulges, loops, or wobble base pairs to modulate the activity of the siNA molecule to mediate RNA interference.

By “blunt ends” is meant symmetric termini or termini of a double-stranded siNA molecule having no overhanging nucleotides. The two strands of a double-stranded siNA molecule align with each other without over-hanging nucleotides at the termini. For example, a blunt ended siNA construct comprises terminal nucleotides that are complementary between the sense and antisense regions of the siNA molecule.

In one embodiment, the invention features a double-stranded short interfering nucleic acid (siNA) molecule that down-regulates expression of a SCD gene, wherein the siNA molecule is assembled from two separate oligonucleotide fragments wherein one fragment comprises the sense region and the second fragment comprises the antisense region of the siNA molecule. The sense region can be connected to the antisense region via a linker molecule, such as a polynucleotide linker or a non-nucleotide linker.

In one embodiment, the invention features double-stranded short interfering nucleic acid (siNA) molecule that down-regulates expression of a SCD gene, wherein the siNA molecule comprises about 15 to about 30 (e.g. about 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, or 30) base pairs, and wherein each strand of the siNA molecule comprises one or more chemical modifications. In another embodiment, one of the strands of the double-stranded siNA molecule comprises a nucleotide sequence that is complementary to a nucleotide sequence of a SCD gene or a portion thereof, and the second strand of the double-stranded siNA molecule comprises a nucleotide sequence substantially similar to the nucleotide sequence or a portion thereof of the SCD gene. In another embodiment, one of the strands of the double-stranded siNA molecule comprises a nucleotide sequence that is complementary to a nucleotide sequence of a SCD gene or portion thereof, and the second strand of the double-stranded siNA molecule comprises a nucleotide sequence substantially similar to the nucleotide sequence or portion thereof of the SCD gene. In another embodiment, each strand of the siNA molecule comprises about 15 to about 30 (e.g. about 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, or 30) nucleotides, and each strand comprises at least about 15 to about 30 (e.g. about 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, or 30) nucleotides that are complementary to the nucleotides of the other strand. The SCD gene can comprise, for example, sequences referred to in Table I.

In one embodiment, an siNA molecule of the invention comprises no ribonucleotides. In another embodiment, an siNA molecule of the invention comprises ribonucleotides.

In one embodiment, an siNA molecule of the invention comprises an antisense region comprising a nucleotide sequence that is complementary to a nucleotide sequence of a SCD gene or a portion thereof, and the siNA further comprises a sense region comprising a nucleotide sequence substantially similar to the nucleotide sequence of the SCD gene or a portion thereof. In another embodiment, the antisense region and the sense region each comprise about 15 to about 30 (e.g. about 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, or 30) nucleotides and the antisense region comprises at least about 15 to about 30 (e.g. about 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, or 30) nucleotides that are complementary to nucleotides of the sense region. The SCD gene can comprise, for example, sequences referred to in Table I. In another embodiment, the siNA is a double-stranded nucleic acid molecule, where each of the two strands of the siNA molecule independently comprise about 15 to about 40 (e.g. about 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 23, 33, 34, 35, 36, 37, 38, 39, or 40) nucleotides, and where one of the strands of the siNA molecule comprises at least about 15 (e.g. about 15, 16, 17, 18, 19, 20, 21, 22, 23, 24 or 25 or more) nucleotides that are complementary to the nucleic acid sequence of the SCD gene or a portion thereof.

In one embodiment, an siNA molecule of the invention comprises a sense region and an antisense region, wherein the antisense region comprises a nucleotide sequence that is complementary to a nucleotide sequence of RNA encoded by a SCD gene, or a portion thereof, and the sense region comprises a nucleotide sequence that is complementary to the antisense region. In one embodiment, the siNA molecule is assembled from two separate oligonucleotide fragments, wherein one fragment comprises the sense region and the second fragment comprises the antisense region of the siNA molecule. In another embodiment, the sense region is connected to the antisense region via a linker molecule. In another embodiment, the sense region is connected to the antisense region via a linker molecule, such as a nucleotide or non-nucleotide linker. The SCD gene can comprise, for example, sequences referred in to Table I.

In one embodiment, the invention features a double-stranded short interfering nucleic acid (siNA) molecule that down-regulates expression of a SCD gene comprising a sense region and an antisense region, wherein the antisense region comprises a nucleotide sequence that is complementary to a nucleotide sequence of RNA encoded by the SCD gene or a portion thereof and the sense region comprises a nucleotide sequence that is complementary to the antisense region, and wherein the siNA molecule has one or more modified pyrimidine and/or purine nucleotides. In one embodiment, the pyrimidine nucleotides in the sense region are 2′-O-methylpyrimidine nucleotides or 2′-deoxy-2′-fluoro pyrimidine nucleotides and the purine nucleotides present in the sense region are 2′-deoxy purine nucleotides. In another embodiment, the pyrimidine nucleotides in the sense region are 2′-deoxy-2′-fluoro pyrimidine nucleotides and the purine nucleotides present in the sense region are 2′-O-methyl purine nucleotides. In another embodiment, the pyrimidine nucleotides in the sense region are 2′-deoxy-2′-fluoro pyrimidine nucleotides and the purine nucleotides present in the sense region are 2′-deoxy purine nucleotides. In one embodiment, the pyrimidine nucleotides in the antisense region are 2′-deoxy-2′-fluoro pyrimidine nucleotides and the purine nucleotides present in the antisense region are 2′-O-methyl or 2′-deoxy purine nucleotides. In another embodiment of any of the above-described siNA molecules, any nucleotides present in a non-complementary region of the sense strand (e.g. overhang region) are 2′-deoxy nucleotides.

In one embodiment, the invention features a double-stranded short interfering nucleic acid (siNA) molecule that down-regulates expression of a SCD gene, wherein the siNA molecule is assembled from two separate oligonucleotide fragments wherein one fragment comprises the sense region and the second fragment comprises the antisense region of the siNA molecule, and wherein the fragment comprising the sense region includes a terminal cap moiety at the 5′-end, the 3′-end, or both of the 5′ and 3′ ends of the fragment. In one embodiment, the terminal cap moiety is an inverted deoxy abasic moiety or glyceryl moiety. In one embodiment, each of the two fragments of the siNA molecule independently comprise about 15 to about 30 (e.g. about 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, or 30) nucleotides. In another embodiment, each of the two fragments of the siNA molecule independently comprise about 15 to about 40 (e.g. about 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 23, 33, 34, 35, 36, 37, 38, 39, or 40) nucleotides. In a non-limiting example, each of the two fragments of the siNA molecule comprise about 21 nucleotides.

In one embodiment, the invention features an siNA molecule comprising at least one modified nucleotide, wherein the modified nucleotide is a 2′-deoxy-2′-fluoro nucleotide. The siNA can be, for example, about 15 to about 40 nucleotides in length. In one embodiment, all pyrimidine nucleotides present in the siNA are 2′-deoxy-2′-fluoro pyrimidine nucleotides. In one embodiment, the modified nucleotides in the siNA include at least one 2′-deoxy-2′-fluoro cytidine or 2′-deoxy-2′-fluoro uridine nucleotide. In another embodiment, the modified nucleotides in the siNA include at least one 2′-deoxy-2′-fluoro cytidine and at least one 2′-deoxy-2′-fluoro uridine nucleotides. In one embodiment, all uridine nucleotides present in the siNA are 2′-deoxy-2′-fluoro uridine nucleotides. In one embodiment, all cytidine nucleotides present in the siNA are 2′-deoxy-2′-fluoro cytidine nucleotides. In one embodiment, all adenosine nucleotides present in the siNA are 2′-deoxy-2′-fluoro adenosine nucleotides. In one embodiment, all guanosine nucleotides present in the siNA are 2′-deoxy-2′-fluoro guanosine nucleotides. The siNA can further comprise at least one modified internucleotidic linkage, such as phosphorothioate linkage. In one embodiment, the 2′-deoxy-2′-fluoronucleotides are present at specifically selected locations in the siNA that are sensitive to cleavage by ribonucleases, such as locations having pyrimidine nucleotides.

In one embodiment, the invention features a method of increasing the stability of an siNA molecule against cleavage by ribonucleases comprising introducing at least one modified nucleotide into the siNA molecule, wherein the modified nucleotide is a 2′-deoxy-2′-fluoro nucleotide. In one embodiment, all pyrimidine nucleotides present in the siNA are 2′-deoxy-2′-fluoro pyrimidine nucleotides. In one embodiment, the modified nucleotides in the siNA include at least one 2′-deoxy-2′-fluoro cytidine or 2′-deoxy-2′-fluoro uridine nucleotide. In another embodiment, the modified nucleotides in the siNA include at least one 2′-deoxy-2′-fluoro cytidine and at least one 2′-deoxy-2′-fluoro uridine nucleotides. In one embodiment, all uridine nucleotides present in the siNA are 2′-deoxy-2′-fluoro uridine nucleotides. In one embodiment, all cytidine nucleotides present in the siNA are 2′-deoxy-2′-fluoro cytidine nucleotides. In one embodiment, all adenosine nucleotides present in the siNA are 2′-deoxy-2′-fluoro adenosine nucleotides. In one embodiment, all guanosine nucleotides present in the siNA are 2′-deoxy-2′-fluoro guanosine nucleotides. The siNA can further comprise at least one modified internucleotidic linkage, such as phosphorothioate linkage. In one embodiment, the 2′-deoxy-2′-fluoronucleotides are present at specifically selected locations in the siNA that are sensitive to cleavage by ribonucleases, such as locations having pyrimidine nucleotides.

In one embodiment, the invention features a double-stranded short interfering nucleic acid (siNA) molecule that down-regulates expression of a SCD gene comprising a sense region and an antisense region, wherein the antisense region comprises a nucleotide sequence that is complementary to a nucleotide sequence of RNA encoded by the SCD gene or a portion thereof and the sense region comprises a nucleotide sequence that is complementary to the antisense region, and wherein the purine nucleotides present in the antisense region comprise 2′-deoxy-purine nucleotides. In an alternative embodiment, the purine nucleotides present in the antisense region comprise 2′-O-methyl purine nucleotides. In either of the above embodiments, the antisense region can comprise a phosphorothioate internucleotide linkage at the 3′ end of the antisense region. Alternatively, in either of the above embodiments, the antisense region can comprise a glyceryl modification at the 3′ end of the antisense region. In another embodiment of any of the above-described siNA molecules, any nucleotides present in a non-complementary region of the antisense strand (e.g. overhang region) are 2′-deoxy nucleotides.

In one embodiment, the antisense region of an siNA molecule of the invention comprises sequence complementary to a portion of a SCD transcript having sequence unique to a particular SCD disease related allele, such as sequence comprising a single nucleotide polymorphism (SNP) associated with the disease specific allele. As such, the antisense region of an siNA molecule of the invention can comprise sequence complementary to sequences that are unique to a particular allele to provide specificity in mediating selective RNAi against the disease, condition, or trait related allele.

In one embodiment, the invention features a double-stranded short interfering nucleic acid (siNA) molecule that down-regulates expression of a SCD gene, wherein the siNA molecule is assembled from two separate oligonucleotide fragments wherein one fragment comprises the sense region and the second fragment comprises the antisense region of the siNA molecule. In another embodiment, the siNA molecule is a double-stranded nucleic acid molecule, where each strand is about 21 nucleotides long and where about 19 nucleotides of each fragment of the siNA molecule are base-paired to the complementary nucleotides of the other fragment of the siNA molecule, wherein at least two 3′ terminal nucleotides of each fragment of the siNA molecule are not base-paired to the nucleotides of the other fragment of the siNA molecule. In another embodiment, the siNA molecule is a double-stranded nucleic acid molecule, where each strand is about 19 nucleotide long and where the nucleotides of each fragment of the siNA molecule are base-paired to the complementary nucleotides of the other fragment of the siNA molecule to form at least about 15 (e.g., 15, 16, 17, 18, or 19) base pairs, wherein one or both ends of the siNA molecule are blunt ends. In one embodiment, each of the two 3′ terminal nucleotides of each fragment of the siNA molecule is a 2′-deoxy-pyrimidine nucleotide, such as a 2′-deoxy-thymidine. In another embodiment, all nucleotides of each fragment of the siNA molecule are base-paired to the complementary nucleotides of the other fragment of the siNA molecule. In another embodiment, the siNA molecule is a double-stranded nucleic acid molecule of about 19 to about 25 base pairs having a sense region and an antisense region, where about 19 nucleotides of the antisense region are base-paired to the nucleotide sequence or a portion thereof of the RNA encoded by the SCD gene. In another embodiment, about 21 nucleotides of the antisense region are base-paired to the nucleotide sequence or a portion thereof of the RNA encoded by the SCD gene. In any of the above embodiments, the 5′-end of the fragment comprising said antisense region can optionally include a phosphate group.

In one embodiment, the invention features a double-stranded short interfering nucleic acid (siNA) molecule that inhibits the expression of a SCD RNA sequence (e.g., wherein said target RNA sequence is encoded by a SCD gene involved in the SCD pathway), wherein the siNA molecule does not contain any ribonucleotides and wherein each strand of the double-stranded siNA molecule is about 15 to about 30 nucleotides. In one embodiment, the siNA molecule is 21 nucleotides in length. Examples of non-ribonucleotide containing siNA constructs are combinations of stabilization chemistries shown in Table IV in any combination of Sense/Antisense chemistries, such as Stab 7/8, Stab 7/11, Stab 8/8, Stab 18/8, Stab 18/11, Stab 12/13, Stab 7/13, Stab 18/13, Stab 7/19, Stab 8/19, Stab 18/19, Stab 7/20, Stab 8/20, Stab 18/20, Stab 7/32, Stab 8/32, or Stab 18/32 (e.g., any siNA having Stab 7, 8, 11, 12, 13, 14, 15, 17, 18, 19, 20, or 32 sense or antisense strands or any combination thereof).

In one embodiment, the invention features a chemically synthesized double-stranded RNA molecule that directs cleavage of a SCD RNA via RNA interference, wherein each strand of said RNA molecule is about 15 to about 30 nucleotides in length; one strand of the RNA molecule comprises nucleotide sequence having sufficient complementarity to the SCD RNA for the RNA molecule to direct cleavage of the SCD RNA via RNA interference; and wherein at least one strand of the RNA molecule optionally comprises one or more chemically modified nucleotides described herein, such as without limitation deoxynucleotides, 2′-O-methyl nucleotides, 2′-deoxy-2′-fluoro nucleotides, 2′-O-methoxyethyl nucleotides etc.

In one embodiment, the invention features a medicament comprising an siNA molecule of the invention.

In one embodiment, the invention features an active ingredient comprising an siNA molecule of the invention.

In one embodiment, the invention features the use of a double-stranded short interfering nucleic acid (siNA) molecule to inhibit, down-regulate, or reduce expression of a SCD gene, wherein the siNA molecule comprises one or more chemical modifications and each strand of the double-stranded siNA is independently about 15 to about 30 or more (e.g., about 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29 or 30 or more) nucleotides long. In one embodiment, the siNA molecule of the invention is a double-stranded nucleic acid molecule comprising one or more chemical modifications, where each of the two fragments of the siNA molecule independently comprise about 15 to about 40 (e.g. about 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 23, 33, 34, 35, 36, 37, 38, 39, or 40) nucleotides and where one of the strands comprises at least 15 nucleotides that are complementary to nucleotide sequence of SCD encoding RNA or a portion thereof. In a non-limiting example, each of the two fragments of the siNA molecule comprise about 21 nucleotides. In another embodiment, the siNA molecule is a double-stranded nucleic acid molecule comprising one or more chemical modifications, where each strand is about 21 nucleotide long and where about 19 nucleotides of each fragment of the siNA molecule are base-paired to the complementary nucleotides of the other fragment of the siNA molecule, wherein at least two 3′ terminal nucleotides of each fragment of the siNA molecule are not base-paired to the nucleotides of the other fragment of the siNA molecule. In another embodiment, the siNA molecule is a double-stranded nucleic acid molecule comprising one or more chemical modifications, where each strand is about 19 nucleotide long and where the nucleotides of each fragment of the siNA molecule are base-paired to the complementary nucleotides of the other fragment of the siNA molecule to form at least about 15 (e.g., 15, 16, 17, 18, or 19) base pairs, wherein one or both ends of the siNA molecule are blunt ends. In one embodiment, each of the two 3′ terminal nucleotides of each fragment of the siNA molecule is a 2′-deoxy-pyrimidine nucleotide, such as a 2′-deoxy-thymidine. In another embodiment, all nucleotides of each fragment of the siNA molecule are base-paired to the complementary nucleotides of the other fragment of the siNA molecule. In another embodiment, the siNA molecule is a double-stranded nucleic acid molecule of about 19 to about 25 base pairs having a sense region and an antisense region and comprising one or more chemical modifications, where about 19 nucleotides of the antisense region are base-paired to the nucleotide sequence or a portion thereof of the RNA encoded by the SCD gene. In another embodiment, about 21 nucleotides of the antisense region are base-paired to the nucleotide sequence or a portion thereof of the RNA encoded by the SCD gene. In any of the above embodiments, the 5′-end of the fragment comprising said antisense region can optionally include a phosphate group.

In one embodiment, the invention features the use of a double-stranded short interfering nucleic acid (siNA) molecule that inhibits, down-regulates, or reduces expression of a SCD gene, wherein one of the strands of the double-stranded siNA molecule is an antisense strand which comprises nucleotide sequence that is complementary to nucleotide sequence of SCD RNA or a portion thereof, the other strand is a sense strand which comprises nucleotide sequence that is complementary to a nucleotide sequence of the antisense strand and wherein a majority of the pyrimidine nucleotides present in the double-stranded siNA molecule comprises a sugar modification.

In one embodiment, the invention features a double-stranded short interfering nucleic acid (siNA) molecule that inhibits, down-regulates, or reduces expression of a SCD gene, wherein one of the strands of the double-stranded siNA molecule is an antisense strand which comprises nucleotide sequence that is complementary to nucleotide sequence of SCD RNA or a portion thereof, wherein the other strand is a sense strand which comprises nucleotide sequence that is complementary to a nucleotide sequence of the antisense strand and wherein a majority of the pyrimidine nucleotides present in the double-stranded siNA molecule comprises a sugar modification.

In one embodiment, the invention features a double-stranded short interfering nucleic acid (siNA) molecule that inhibits, down-regulates, or reduces expression of a SCD gene, wherein one of the strands of the double-stranded siNA molecule is an antisense strand which comprises nucleotide sequence that is complementary to nucleotide sequence of SCD RNA that encodes a protein or portion thereof, the other strand is a sense strand which comprises nucleotide sequence that is complementary to a nucleotide sequence of the antisense strand and wherein a majority of the pyrimidine nucleotides present in the double-stranded siNA molecule comprises a sugar modification. In one embodiment, each strand of the siNA molecule comprises about 15 to about 30 or more (e.g., about 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, or 30 or more) nucleotides, wherein each strand comprises at least about 15 nucleotides that are complementary to the nucleotides of the other strand. In one embodiment, the siNA molecule is assembled from two oligonucleotide fragments, wherein one fragment comprises the nucleotide sequence of the antisense strand of the siNA molecule and a second fragment comprises nucleotide sequence of the sense region of the siNA molecule. In one embodiment, the sense strand is connected to the antisense strand via a linker molecule, such as a polynucleotide linker or a non-nucleotide linker. In a further embodiment, the pyrimidine nucleotides present in the sense strand are 2′-deoxy-2′fluoro pyrimidine nucleotides and the purine nucleotides present in the sense region are 2′-deoxy purine nucleotides. In another embodiment, the pyrimidine nucleotides present in the sense strand are 2′-deoxy-2′fluoro pyrimidine nucleotides and the purine nucleotides present in the sense region are 2′-O-methyl purine nucleotides. In still another embodiment, the pyrimidine nucleotides present in the antisense strand are 2′-deoxy-2′-fluoro pyrimidine nucleotides and any purine nucleotides present in the antisense strand are 2′-deoxy purine nucleotides. In another embodiment, the antisense strand comprises one or more 2′-deoxy-2′-fluoro pyrimidine nucleotides and one or more 2′-O-methyl purine nucleotides. In another embodiment, the pyrimidine nucleotides present in the antisense strand are 2′-deoxy-2′-fluoro pyrimidine nucleotides and any purine nucleotides present in the antisense strand are 2′-O-methyl purine nucleotides. In a further embodiment the sense strand comprises a 3′-end and a 5′-end, wherein a terminal cap moiety (e.g., an inverted deoxy abasic moiety or inverted deoxy nucleotide moiety such as inverted thymidine) is present at the 5′-end, the 3′-end, or both of the 5′ and 3′ ends of the sense strand. In another embodiment, the antisense strand comprises a phosphorothioate internucleotide linkage at the 3′ end of the antisense strand. In another embodiment, the antisense strand comprises a glyceryl modification at the 3′ end. In another embodiment, the 5′-end of the antisense strand optionally includes a phosphate group.

In any of the above-described embodiments of a double-stranded short interfering nucleic acid (siNA) molecule that inhibits expression of a SCD gene, wherein a majority of the pyrimidine nucleotides present in the double-stranded siNA molecule comprises a sugar modification, each of the two strands of the siNA molecule can comprise about 15 to about 30 or more (e.g., about 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, or 30 or more) nucleotides. In one embodiment, about 15 to about 30 or more (e.g., about 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, or 30 or more) nucleotides of each strand of the siNA molecule are base-paired to the complementary nucleotides of the other strand of the siNA molecule. In another embodiment, about 15 to about 30 or more (e.g., about 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, or 30 or more) nucleotides of each strand of the siNA molecule are base-paired to the complementary nucleotides of the other strand of the siNA molecule, wherein at least two 3′ terminal nucleotides of each strand of the siNA molecule are not base-paired to the nucleotides of the other strand of the siNA molecule. In another embodiment, each of the two 3′ terminal nucleotides of each fragment of the siNA molecule is a 2′-deoxy-pyrimidine, such as 2′-deoxy-thymidine. In one embodiment, each strand of the siNA molecule is base-paired to the complementary nucleotides of the other strand of the siNA molecule. In one embodiment, about 15 to about 30 (e.g., about 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, or 30) nucleotides of the antisense strand are base-paired to the nucleotide sequence of the SCD RNA or a portion thereof. In one embodiment, about 18 to about 25 (e.g., about 18, 19, 20, 21, 22, 23, 24, or 25) nucleotides of the antisense strand are base-paired to the nucleotide sequence of the SCD RNA or a portion thereof.

In one embodiment, the invention features a double-stranded short interfering nucleic acid (siNA) molecule that inhibits expression of a SCD gene, wherein one of the strands of the double-stranded siNA molecule is an antisense strand which comprises nucleotide sequence that is complementary to nucleotide sequence of SCD RNA or a portion thereof, the other strand is a sense strand which comprises nucleotide sequence that is complementary to a nucleotide sequence of the antisense strand and wherein a majority of the pyrimidine nucleotides present in the double-stranded siNA molecule comprises a sugar modification, and wherein the 5′-end of the antisense strand optionally includes a phosphate group.

In one embodiment, the invention features a double-stranded short interfering nucleic acid (siNA) molecule that inhibits expression of a SCD gene, wherein one of the strands of the double-stranded siNA molecule is an antisense strand which comprises nucleotide sequence that is complementary to nucleotide sequence of SCD RNA or a portion thereof, the other strand is a sense strand which comprises nucleotide sequence that is complementary to a nucleotide sequence of the antisense strand and wherein a majority of the pyrimidine nucleotides present in the double-stranded siNA molecule comprises a sugar modification, and wherein the nucleotide sequence or a portion thereof of the antisense strand is complementary to a nucleotide sequence of the untranslated region or a portion thereof of the SCD RNA.

In one embodiment, the invention features a double-stranded short interfering nucleic acid (siNA) molecule that inhibits expression of a SCD gene, wherein one of the strands of the double-stranded siNA molecule is an antisense strand which comprises nucleotide sequence that is complementary to nucleotide sequence of SCD RNA or a portion thereof, wherein the other strand is a sense strand which comprises nucleotide sequence that is complementary to a nucleotide sequence of the antisense strand, wherein a majority of the pyrimidine nucleotides present in the double-stranded siNA molecule comprises a sugar modification, and wherein the nucleotide sequence of the antisense strand is complementary to a nucleotide sequence of the SCD RNA or a portion thereof that is present in the SCD RNA.

In one embodiment, the invention features a composition comprising an siNA molecule of the invention in a pharmaceutically acceptable carrier or diluent.

In a non-limiting example, the introduction of chemically modified nucleotides into nucleic acid molecules provides a powerful tool in overcoming potential limitations of in vivo stability and bioavailability inherent to native RNA molecules that are delivered exogenously. For example, the use of chemically modified nucleic acid molecules can enable a lower dose of a particular nucleic acid molecule for a given therapeutic effect since chemically modified nucleic acid molecules tend to have a longer half-life in serum. Furthermore, certain chemical modifications can improve the bioavailability of nucleic acid molecules by targeting particular cells or tissues and/or improving cellular uptake of the nucleic acid molecule. Therefore, even if the activity of a chemically modified nucleic acid molecule is reduced as compared to a native nucleic acid molecule, for example, when compared to an all-RNA nucleic acid molecule, the overall activity of the modified nucleic acid molecule can be greater than that of the native molecule due to improved stability and/or delivery of the molecule. Unlike native unmodified siNA, chemically modified siNA can also minimize the possibility of activating interferon activity in humans.

In any of the embodiments of siNA molecules described herein, the antisense region of an siNA molecule of the invention can comprise a phosphorothioate internucleotide linkage at the 3′-end of said antisense region. In any of the embodiments of siNA molecules described herein, the antisense region can comprise about one to about five phosphorothioate internucleotide linkages at the 5′-end of said antisense region. In any of the embodiments of siNA molecules described herein, the 3′-terminal nucleotide overhangs of an siNA molecule of the invention can comprise ribonucleotides or deoxyribonucleotides that are chemically modified at a nucleic acid sugar, base, or backbone. In any of the embodiments of siNA molecules described herein, the 3′-terminal nucleotide overhangs can comprise one or more universal base ribonucleotides. In any of the embodiments of siNA molecules described herein, the 3′-terminal nucleotide overhangs can comprise one or more acyclic nucleotides.

One embodiment of the invention provides an expression vector comprising a nucleic acid sequence encoding at least one siNA molecule of the invention in a manner that allows expression of the nucleic acid molecule. Another embodiment of the invention provides a mammalian cell comprising such an expression vector. The mammalian cell can be a human cell. The siNA molecule of the expression vector can comprise a sense region and an antisense region. The antisense region can comprise sequence complementary to a RNA or DNA sequence encoding SCD and the sense region can comprise sequence complementary to the antisense region. The siNA molecule can comprise two distinct strands having complementary sense and antisense regions. The siNA molecule can comprise a single strand having complementary sense and antisense regions.

In one embodiment, the invention features a chemically modified short interfering nucleic acid (siNA) molecule capable of mediating RNA interference (RNAi) against SCD inside a cell or reconstituted in vitro system, wherein the chemical modification comprises one or more (e.g., about 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, or more) nucleotides comprising a backbone modified internucleotide linkage having Formula I:

wherein each R1 and R2 is independently any nucleotide, non-nucleotide, or polynucleotide which can be naturally-occurring or chemically modified, each X and Y is independently O, S, N, alkyl, or substituted alkyl, each Z and W is independently O, S, N, alkyl, substituted alkyl, O-alkyl, S-alkyl, alkaryl, aralkyl, or acetyl and wherein W, X, Y, and Z are optionally not all O. In another embodiment, a backbone modification of the invention comprises a phosphonoacetate and/or thiophosphonoacetate internucleotide linkage (see for example Sheehan et al., 2003, Nucleic Acids Research, 31, 4109-4118).

The chemically modified internucleotide linkages having Formula I, for example, wherein any Z, W, X, and/or Y independently comprises a sulphur atom, can be present in one or both oligonucleotide strands of the siNA duplex, for example, in the sense strand, the antisense strand, or both strands. The siNA molecules of the invention can comprise one or more (e.g., about 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, or more) chemically modified internucleotide linkages having Formula I at the 3′-end, the 5′-end, or both of the 3′ and 5′-ends of the sense strand, the antisense strand, or both strands. For example, an exemplary siNA molecule of the invention can comprise about 1 to about 5 or more (e.g., about 1, 2, 3, 4, 5, or more) chemically modified internucleotide linkages having Formula I at the 5′-end of the sense strand, the antisense strand, or both strands. In another non-limiting example, an exemplary siNA molecule of the invention can comprise one or more (e.g., about 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, or more) pyrimidine nucleotides with chemically modified internucleotide linkages having Formula I in the sense strand, the antisense strand, or both strands. In yet another non-limiting example, an exemplary siNA molecule of the invention can comprise one or more (e.g., about 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, or more) purine nucleotides with chemically modified internucleotide linkages having Formula I in the sense strand, the antisense strand, or both strands. In another embodiment, an siNA molecule of the invention having internucleotide linkage(s) of Formula I also comprises a chemically modified nucleotide or non-nucleotide having any of Formulae I-VII.

In one embodiment, the invention features a chemically modified short interfering nucleic acid (siNA) molecule capable of mediating RNA interference (RNAi) against SCD inside a cell or reconstituted in vitro system, wherein the chemical modification comprises one or more (e.g., about 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, or more) nucleotides or non-nucleotides having Formula II:

wherein each R3, R4, R5, R6, R7, R8, R10, R1 and R12 is independently H, OH, alkyl, substituted alkyl, alkaryl or aralkyl, F, Cl, Br, CN, CF3, OCF3, OCN, O-alkyl, S-alkyl, N-alkyl, O-alkenyl, S-alkenyl, N-alkenyl, SO-alkyl, alkyl-SH, alkyl-OH, O-alkyl-OH, O-alkyl-SH, S-alkyl-OH, S-alkyl-SH, alkyl-S-alkyl, alkyl-O-alkyl, ONO2, NO2, N3, NH2, aminoalkyl, aminoacid, aminoacyl, ONH2, O-aminoalkyl, O-aminoacid, O-aminoacyl, heterocycloalkyl, heterocycloalkaryl, aminoalkylamino, poly-alkylamino, substituted silyl, or group having Formula I or II; R9 is O, S, CH2, S═O, CHF, or CF2, and B is a nucleosidic base such as adenine, guanine, uracil, cytosine, thymine, 2-aminoadenosine, 5-methylcytosine, 2,6-diaminopurine, or any other non-naturally occurring base that can be complementary or non-complementary to target RNA or a non-nucleosidic base such as phenyl, naphthyl, 3-nitropyrrole, 5-nitroindole, nebularine, pyridone, pyridinone, or any other non-naturally occurring universal base that can be complementary or non-complementary to target RNA.

The chemically modified nucleotide or non-nucleotide of Formula II can be present in one or both oligonucleotide strands of the siNA duplex, for example in the sense strand, the antisense strand, or both strands. The siNA molecules of the invention can comprise one or more chemically modified nucleotides or non-nucleotides of Formula II at the 3′-end, the 5′-end, or both of the 3′ and 5′-ends of the sense strand, the anti sense strand, or both strands. For example, an exemplary siNA molecule of the invention can comprise about 1 to about 5 or more (e.g., about 1, 2, 3, 4, 5, or more) chemically modified nucleotides or non-nucleotides of Formula II at the 5′-end of the sense strand, the antisense strand, or both strands. In another non-limiting example, an exemplary siNA molecule of the invention can comprise about 1 to about 5 or more (e.g., about 1, 2, 3, 4, 5, or more) chemically modified nucleotides or non-nucleotides of Formula II at the 3′-end of the sense strand, the antisense strand, or both strands.

In one embodiment, the invention features a chemically modified short interfering nucleic acid (siNA) molecule capable of mediating RNA interference (RNAi) against SCD inside a cell or reconstituted in vitro system, wherein the chemical modification comprises one or more (e.g., about 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, or more) nucleotides or non-nucleotides having Formula III:

wherein each R3, R4, R5, R6, R7, R8, R10, R11 and R12 is independently H, OH, alkyl, substituted alkyl, alkaryl or aralkyl, F, Cl, Br, CN, CF3, OCF3, OCN, O-alkyl, S-alkyl, N-alkyl, O-alkenyl, S-alkenyl, N-alkenyl, SO-alkyl, alkyl-SH, alkyl-OH, O-alkyl-OH, O-alkyl-SH, S-alkyl-OH, S-alkyl-SH, alkyl-S-alkyl, alkyl-O-alkyl, ONO2, NO2, N3, NH2, aminoalkyl, aminoacid, aminoacyl, ONH2, O-aminoalkyl, O-aminoacid, O-aminoacyl, heterocycloalkyl, heterocycloalkaryl, aminoalkylamino, poly-alkylamino, substituted silyl, or group having Formula I or II; R9 is O, S, CH2, S═O, CHF, or CF2, and B is a nucleosidic base such as adenine, guanine, uracil, cytosine, thymine, 2-aminoadenosine, 5-methylcytosine, 2,6-diaminopurine, or any other non-naturally occurring base that can be employed to be complementary or non-complementary to target RNA or a non-nucleosidic base such as phenyl, naphthyl, 3-nitropyrrole, 5-nitroindole, nebularine, pyridone, pyridinone, or any other non-naturally occurring universal base that can be complementary or non-complementary to target RNA.

The chemically modified nucleotide or non-nucleotide of Formula III can be present in one or both oligonucleotide strands of the siNA duplex, for example, in the sense strand, the antisense strand, or both strands. The siNA molecules of the invention can comprise one or more chemically modified nucleotides or non-nucleotides of Formula III at the 3′-end, the 5′-end, or both of the 3′ and 5′-ends of the sense strand, the antisense strand, or both strands. For example, an exemplary siNA molecule of the invention can comprise about 1 to about 5 or more (e.g., about 1, 2, 3, 4, 5, or more) chemically modified nucleotide(s) or non-nucleotide(s) of Formula III at the 5′-end of the sense strand, the antisense strand, or both strands. In another non-limiting example, an exemplary siNA molecule of the invention can comprise about 1 to about 5 or more (e.g., about 1, 2, 3, 4, 5, or more) chemically modified nucleotide or non-nucleotide of Formula III at the 3′-end of the sense strand, the antisense strand, or both strands.

In another embodiment, an siNA molecule of the invention comprises a nucleotide having Formula II or III, wherein the nucleotide having Formula II or III is in an inverted configuration. For example, the nucleotide having Formula II or III is connected to the siNA construct in a 3′-3′,3′-2′,2′-3′, or 5′-5′ configuration, such as at the 3′-end, the 5′-end, or both of the 3′ and 5′-ends of one or both siNA strands.

In one embodiment, the invention features a chemically modified short interfering nucleic acid (siNA) molecule capable of mediating RNA interference (RNAi) against SCD inside a cell or reconstituted in vitro system, wherein the chemical modification comprises a 5′-terminal phosphate group having Formula IV:

wherein each X and Y is independently O, S, N, alkyl, substituted alkyl, or alkylhalo; wherein each Z and W is independently O, S, N, alkyl, substituted alkyl, O-alkyl, S-alkyl, alkaryl, aralkyl, alkylhalo, or acetyl; and wherein W, X, Y and Z are not all O.

In one embodiment, the invention features an siNA molecule having a 5′-terminal phosphate group having Formula IV on the target-complementary strand, for example, a strand complementary to a target RNA, wherein the siNA molecule comprises an all RNA siNA molecule. In another embodiment, the invention features an siNA molecule having a 5′-terminal phosphate group having Formula IV on the target-complementary strand wherein the siNA molecule also comprises about 1 to about 3 (e.g., about 1, 2, or 3) nucleotide 3′-terminal nucleotide overhangs having about 1 to about 4 (e.g., about 1, 2, 3, or 4) deoxyribonucleotides on the 3′-end of one or both strands. In another embodiment, a 5′-terminal phosphate group having Formula IV is present on the target-complementary strand of an siNA molecule of the invention, for example an siNA molecule having chemical modifications having any of Formulae I-VIII.

In one embodiment, the invention features a chemically modified short interfering nucleic acid (siNA) molecule capable of mediating RNA interference (RNAi) against SCD inside a cell or reconstituted in vitro system, wherein the chemical modification comprises one or more phosphorothioate internucleotide linkages. For example, in a non-limiting example, the invention features a chemically modified short interfering nucleic acid (siNA) having about 1, 2, 3, 4, 5, 6, 7, 8 or more phosphorothioate internucleotide linkages in one siNA strand. In yet another embodiment, the invention features a chemically modified short interfering nucleic acid (siNA) individually having about 1, 2, 3, 4, 5, 6, 7, 8 or more phosphorothioate internucleotide linkages in both siNA strands. The phosphorothioate internucleotide linkages can be present in one or both oligonucleotide strands of the siNA duplex, for example in the sense strand, the antisense strand, or both strands. The siNA molecules of the invention can comprise one or more phosphorothioate internucleotide linkages at the 3′-end, the 5′-end, or both of the 3′- and 5′-ends of the sense strand, the antisense strand, or both strands. For example, an exemplary siNA molecule of the invention can comprise about 1 to about 5 or more (e.g., about 1, 2, 3, 4, 5, or more) consecutive phosphorothioate internucleotide linkages at the 5′-end of the sense strand, the antisense strand, or both strands. In another non-limiting example, an exemplary siNA molecule of the invention can comprise one or more (e.g., about 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, or more) pyrimidine phosphorothioate internucleotide linkages in the sense strand, the antisense strand, or both strands. In yet another non-limiting example, an exemplary siNA molecule of the invention can comprise one or more (e.g., about 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, or more) purine phosphorothioate internucleotide linkages in the sense strand, the antisense strand, or both strands.

In one embodiment, the invention features an siNA molecule, wherein the sense strand comprises one or more, for example, about 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, or more phosphorothioate internucleotide linkages, and/or one or more (e.g., about 1, 2, 3, 4, 5, 6, 7, 8, 9, 10 or more) 2′-deoxy, 2′-O-methyl, 2′-deoxy-2′-fluoro, and/or about one or more (e.g., about 1, 2, 3, 4, 5, 6, 7, 8, 9, 10 or more) universal base modified nucleotides, and optionally a terminal cap molecule at the 3′-end, the 5′-end, or both of the 3′- and 5′-ends of the sense strand; and wherein the antisense strand comprises about 1 to about 10 or more, specifically about 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, or more phosphorothioate internucleotide linkages, and/or one or more (e.g., about 1, 2, 3, 4, 5, 6, 7, 8, 9, 10 or more) 2′-deoxy, 2′-O-methyl, 2′-deoxy-2′-fluoro, and/or one or more (e.g., about 1, 2, 3, 4, 5, 6, 7, 8, 9, 10 or more) universal base modified nucleotides, and optionally a terminal cap molecule at the 3′-end, the 5′-end, or both of the 3′- and 5′-ends of the antisense strand. In another embodiment, one or more, for example about 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, or more, pyrimidine nucleotides of the sense and/or antisense siNA strand are chemically modified with 2′-deoxy, 2′-O-methyl and/or 2′-deoxy-2′-fluoro nucleotides, with or without one or more, for example about 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, or more, phosphorothioate internucleotide linkages and/or a terminal cap molecule at the 3′-end, the 5′-end, or both of the 3′- and 5′-ends, being present in the same or different strand.

In another embodiment, the invention features an siNA molecule, wherein the sense strand comprises about 1 to about 5, specifically about 1, 2, 3, 4, or 5 phosphorothioate internucleotide linkages, and/or one or more (e.g., about 1, 2, 3, 4, 5, or more) 2′-deoxy, 2′-O-methyl, 2′-deoxy-2′-fluoro, and/or one or more (e.g., about 1, 2, 3, 4, 5, or more) universal base modified nucleotides, and optionally a terminal cap molecule at the 3-end, the 5′-end, or both of the 3′- and 5′-ends of the sense strand; and wherein the antisense strand comprises about 1 to about 5 or more, specifically about 1, 2, 3, 4, 5, or more phosphorothioate internucleotide linkages, and/or one or more (e.g., about 1, 2, 3, 4, 5, 6, 7, 8, 9, 10 or more) 2′-deoxy, 2′-O-methyl, 2′-deoxy-2′-fluoro, and/or one or more (e.g., about 1, 2, 3, 4, 5, 6, 7, 8, 9, 10 or more) universal base modified nucleotides, and optionally a terminal cap molecule at the 3′-end, the 5′-end, or both of the 3′- and 5′-ends of the antisense strand. In another embodiment, one or more, for example about 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, or more, pyrimidine nucleotides of the sense and/or antisense siNA strand are chemically modified with 2′-deoxy, 2′-O-methyl and/or 2′-deoxy-2′-fluoro nucleotides, with or without about 1 to about 5 or more, for example about 1, 2, 3, 4, 5, or more phosphorothioate internucleotide linkages and/or a terminal cap molecule at the 3′-end, the 5′-end, or both of the 3′- and 5′-ends, being present in the same or different strand.

In one embodiment, the invention features an siNA molecule, wherein the antisense strand comprises one or more, for example, about 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, or more phosphorothioate internucleotide linkages, and/or about one or more (e.g., about 1, 2, 3, 4, 5, 6, 7, 8, 9, 10 or more) 2′-deoxy, 2′-O-methyl, 2′-deoxy-2′-fluoro, and/or one or more (e.g., about 1, 2, 3, 4, 5, 6, 7, 8, 9, 10 or more) universal base modified nucleotides, and optionally a terminal cap molecule at the 3′-end, the 5′-end, or both of the 3′- and 5′-ends of the sense strand; and wherein the antisense strand comprises about 1 to about 10 or more, specifically about 1, 2, 3, 4, 5, 6, 7, 8, 9, 10 or more phosphorothioate internucleotide linkages, and/or one or more (e.g., about 1, 2, 3, 4, 5, 6, 7, 8, 9, 10 or more) 2′-deoxy, 2′-O-methyl, 2′-deoxy-2′-fluoro, and/or one or more (e.g., about 1, 2, 3, 4, 5, 6, 7, 8, 9, 10 or more) universal base modified nucleotides, and optionally a terminal cap molecule at the 3′-end, the 5′-end, or both of the 3′- and 5′-ends of the antisense strand. In another embodiment, one or more, for example about 1, 2, 3, 4, 5, 6, 7, 8, 9, 10 or more pyrimidine nucleotides of the sense and/or antisense siNA strand are chemically modified with 2′-deoxy, 2′-O-methyl and/or 2′-deoxy-2′-fluoro nucleotides, with or without one or more, for example, about 1, 2, 3, 4, 5, 6, 7, 8, 9, 10 or more phosphorothioate internucleotide linkages and/or a terminal cap molecule at the 3′-end, the 5′-end, or both of the 3′ and 5′-ends, being present in the same or different strand.

In another embodiment, the invention features an siNA molecule, wherein the antisense strand comprises about 1 to about 5 or more, specifically about 1, 2, 3, 4, 5 or more phosphorothioate internucleotide linkages, and/or one or more (e.g., about 1, 2, 3, 4, 5, 6, 7, 8, 9, 10 or more) 2′-deoxy, 2′-O-methyl, 2′-deoxy-2′-fluoro, and/or one or more (e.g., about 1, 2, 3, 4, 5, 6, 7, 8, 9, 10 or more) universal base modified nucleotides, and optionally a terminal cap molecule at the 3′-end, the 5′-end, or both of the 3′- and 5′-ends of the sense strand; and wherein the antisense strand comprises about 1 to about 5 or more, specifically about 1, 2, 3, 4, 5 or more phosphorothioate internucleotide linkages, and/or one or more (e.g., about 1, 2, 3, 4, 5, 6, 7, 8, 9, 10 or more) 2′-deoxy, 2′-O-methyl, 2′-deoxy-2′-fluoro, and/or one or more (e.g., about 1, 2, 3, 4, 5, 6, 7, 8, 9, 10 or more) universal base modified nucleotides, and optionally a terminal cap molecule at the 3′-end, the 5′-end, or both of the 3′- and 5′-ends of the antisense strand. In another embodiment, one or more, for example about 1, 2, 3, 4, 5, 6, 7, 8, 9, 10 or more pyrimidine nucleotides of the sense and/or antisense siNA strand are chemically modified with 2′-deoxy, 2′-O-methyl and/or 2′-deoxy-2′-fluoro nucleotides, with or without about 1 to about 5, for example about 1, 2, 3, 4, 5 or more phosphorothioate internucleotide linkages and/or a terminal cap molecule at the 3′-end, the 5′-end, or both of the 3′- and 5′-ends, being present in the same or different strand.

In one embodiment, the invention features a chemically modified short interfering nucleic acid (siNA) molecule having about 1 to about 5 or more (specifically about 1, 2, 3, 4, 5 or more) phosphorothioate internucleotide linkages in each strand of the siNA molecule.

In another embodiment, the invention features an siNA molecule comprising 2′-5′ internucleotide linkages. The 2′-5′ internucleotide linkage(s) can be at the 3′-end, the 5′-end, or both of the 3′- and 5′-ends of one or both siNA sequence strands. In addition, the 2′-5′ internucleotide linkage(s) can be present at various other positions within one or both siNA sequence strands, for example, about 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, or more including every internucleotide linkage of a pyrimidine nucleotide in one or both strands of the siNA molecule can comprise a 2′-5′ internucleotide linkage, or about 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, or more including every internucleotide linkage of a purine nucleotide in one or both strands of the siNA molecule can comprise a 2′-5′ internucleotide linkage.

In another embodiment, a chemically modified siNA molecule of the invention comprises a duplex having two strands, one or both of which can be chemically modified, wherein each strand is independently about 15 to about 30 (e.g., about 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, or 30) nucleotides in length, wherein the duplex has about 15 to about 30 (e.g., about 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, or 30) base pairs, and wherein the chemical modification comprises a structure having any of Formulae I-VII. For example, an exemplary chemically modified siNA molecule of the invention comprises a duplex having two strands, one or both of which can be chemically modified with a chemical modification having any of Formulae I-VII or any combination thereof, wherein each strand consists of about 21 nucleotides, each having a 2-nucleotide 3′-terminal nucleotide overhang, and wherein the duplex has about 19 base pairs. In another embodiment, an siNA molecule of the invention comprises a single-stranded hairpin structure, wherein the siNA is about 36 to about 70 (e.g., about 36, 40, 45, 50, 55, 60, 65, or 70) nucleotides in length having about 15 to about 30 (e.g., about 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, or 30) base pairs, and wherein the siNA can include a chemical modification comprising a structure having any of Formulae I-VII or any combination thereof. For example, an exemplary chemically modified siNA molecule of the invention comprises a linear oligonucleotide having about 42 to about 50 (e.g., about 42, 43, 44, 45, 46, 47, 48, 49, or 50) nucleotides that is chemically modified with a chemical modification having any of Formulae I-VII or any combination thereof, wherein the linear oligonucleotide forms a hairpin structure having about 19 to about 21 (e.g., 19, 20, or 21) base pairs and a 2-nucleotide 3′-terminal nucleotide overhang. In another embodiment, a linear hairpin siNA molecule of the invention contains a stem loop motif, wherein the loop portion of the siNA molecule is biodegradable. For example, a linear hairpin siNA molecule of the invention is designed such that degradation of the loop portion of the siNA molecule in vivo can generate a double-stranded siNA molecule with 3′-terminal overhangs, such as 3′-terminal nucleotide overhangs comprising about 2 nucleotides.

In another embodiment, an siNA molecule of the invention comprises a hairpin structure, wherein the siNA is about 25 to about 50 (e.g., about 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, or 50) nucleotides in length having about 3 to about 25 (e.g., about 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, or 25) base pairs, and wherein the siNA can include one or more chemical modifications comprising a structure having any of Formulae I-VII or any combination thereof. For example, an exemplary chemically modified siNA molecule of the invention comprises a linear oligonucleotide having about 25 to about 35 (e.g., about 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, or 35) nucleotides that is chemically modified with one or more chemical modifications having any of Formulae I-VII or any combination thereof, wherein the linear oligonucleotide forms a hairpin structure having about 3 to about 25 (e.g., about 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, or 25) base pairs and a 5′-terminal phosphate group that can be chemically modified as described herein (for example a 5′-terminal phosphate group having Formula IV). In another embodiment, a linear hairpin siNA molecule of the invention contains a stem loop motif, wherein the loop portion of the siNA molecule is biodegradable. In one embodiment, a linear hairpin siNA molecule of the invention comprises a loop portion comprising a non-nucleotide linker.

In another embodiment, an siNA molecule of the invention comprises an asymmetric hairpin structure, wherein the siNA is about 25 to about 50 (e.g., about 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, or 50) nucleotides in length having about 3 to about 25 (e.g., about 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, or 25) base pairs, and wherein the siNA can include one or more chemical modifications comprising a structure having any of Formulae I-VII or any combination thereof. For example, an exemplary chemically modified siNA molecule of the invention comprises a linear oligonucleotide having about 25 to about 35 (e.g., about 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, or 35) nucleotides that is chemically modified with one or more chemical modifications having any of Formulae I-VII or any combination thereof, wherein the linear oligonucleotide forms an asymmetric hairpin structure having about 3 to about 25 (e.g., about 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, or 25) base pairs and a 5′-terminal phosphate group that can be chemically modified as described herein (for example a 5′-terminal phosphate group having Formula IV). In one embodiment, an asymmetric hairpin siNA molecule of the invention contains a stem loop motif, wherein the loop portion of the siNA molecule is biodegradable. In another embodiment, an asymmetric hairpin siNA molecule of the invention comprises a loop portion comprising a non-nucleotide linker.

In another embodiment, an siNA molecule of the invention comprises an asymmetric double-stranded structure having separate polynucleotide strands comprising sense and antisense regions, wherein the antisense region is about 15 to about 30 (e.g., about 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, or 30) nucleotides in length, wherein the sense region is about 3 to about 25 (e.g., about 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, or 25) nucleotides in length, wherein the sense region and the antisense region have at least 3 complementary nucleotides, and wherein the siNA can include one or more chemical modifications comprising a structure having any of Formulae I-VII or any combination thereof. For example, an exemplary chemically modified siNA molecule of the invention comprises an asymmetric double-stranded structure having separate polynucleotide strands comprising sense and antisense regions, wherein the antisense region is about 18 to about 23 (e.g., about 18, 19, 20, 21, 22, or 23) nucleotides in length and wherein the sense region is about 3 to about 15 (e.g., about 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, or 15) nucleotides in length, wherein the sense region the antisense region have at least 3 complementary nucleotides, and wherein the siNA can include one or more chemical modifications comprising a structure having any of Formulae I-VII or any combination thereof. In another embodiment, the asymmetric double-stranded siNA molecule can also have a 5′-terminal phosphate group that can be chemically modified as described herein (for example a 5′-terminal phosphate group having Formula IV).

In another embodiment, an siNA molecule of the invention comprises a circular nucleic acid molecule, wherein the siNA is about 38 to about 70 (e.g., about 38, 40, 45, 50, 55, 60, 65, or 70) nucleotides in length having about 15 to about 30 (e.g., about 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, or 30) base pairs, and wherein the siNA can include a chemical modification, which comprises a structure having any of Formulae I-VII or any combination thereof. For example, an exemplary chemically modified siNA molecule of the invention comprises a circular oligonucleotide having about 42 to about 50 (e.g., about 42, 43, 44, 45, 46, 47, 48, 49, or 50) nucleotides that is chemically modified with a chemical modification having any of Formulae I-VII or any combination thereof, wherein the circular oligonucleotide forms a dumbbell shaped structure having about 19 base pairs and 2 loops.

In another embodiment, a circular siNA molecule of the invention contains two loop motifs, wherein one or both loop portions of the siNA molecule is biodegradable. For example, a circular siNA molecule of the invention is designed such that degradation of the loop portions of the siNA molecule in vivo can generate a double-stranded siNA molecule with 3′-terminal overhangs, such as 3′-terminal nucleotide overhangs comprising about 2 nucleotides.

In one embodiment, an siNA molecule of the invention comprises at least one (e.g., about 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, or more) abasic moiety, for example a compound having Formula V:

wherein each R3, R4, R5, R6, R7, R8, R10, R11, R12, and R13 is independently H, OH, alkyl, substituted alkyl, alkaryl or aralkyl, F, Cl, Br, CN, CF3, OCF3, OCN, O-alkyl, S-alkyl, N-alkyl, O-alkenyl, S-alkenyl, N-alkenyl, SO-alkyl, alkyl-SH, alkyl-OH, O-alkyl-OH, O-alkyl-SH, S-alkyl-OH, S-alkyl-SH, alkyl-S-alkyl, alkyl-O-alkyl, ONO2, NO2, N3, NH2, aminoalkyl, aminoacid, aminoacyl, ONH2, O-aminoalkyl, O-aminoacid, O-aminoacyl, heterocycloalkyl, heterocycloalkaryl, aminoalkylamino, poly-alkylamino, substituted silyl, or group having Formula I or II; R9 is O, S, CH2, S═O, CHF, or CF2.

In one embodiment, an siNA molecule of the invention comprises at least one (e.g., about 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, or more) inverted abasic moiety, for example a compound having Formula VI:

wherein each R3, R4, R5, R6, R7, R8, R10, R11, R12, and R13 is independently H, OH, alkyl, substituted alkyl, alkaryl or aralkyl, F, Cl, Br, CN, CF3, OCF3, OCN, O-alkyl, S-alkyl, N-alkyl, O-alkenyl, S-alkenyl, N-alkenyl, SO-alkyl, alkyl-SH, alkyl-OH, O-alkyl-OH, O-alkyl-SH, S-alkyl-OH, S-alkyl-SH, alkyl-S-alkyl, alkyl-O-alkyl, ONO2, NO2, N3, NH2, aminoalkyl, aminoacid, aminoacyl, ONH2, O-aminoalkyl, O-aminoacid, O-aminoacyl, heterocycloalkyl, heterocycloalkaryl, aminoalkylamino, poly-alkylamino, substituted silyl, or group having Formula I or II; R9 is O, S, CH2, S═O, CHF, or CF2, and either R5, R3, R8 or R13 serves as a point of attachment to the siNA molecule of the invention.

In another embodiment, an siNA molecule of the invention comprises at least one (e.g., about 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, or more) substituted polyalkyl moieties, for example a compound having Formula VII:

wherein each n is independently an integer from 1 to 12, each R1, R2 and R3 is independently H, OH, alkyl, substituted alkyl, alkaryl or aralkyl, F, Cl, Br, CN, CF3, OCF3, OCN, O-alkyl, S-alkyl, N-alkyl, O-alkenyl, S-alkenyl, N-alkenyl, SO-alkyl, alkyl-SH, alkyl-OH, O-alkyl-OH, O-alkyl-SH, S-alkyl-OH, S-alkyl-SH, alkyl-S-alkyl, alkyl-O-alkyl, ONO2, NO2, N3, NH2, aminoalkyl, aminoacid, aminoacyl, ONH2, O-aminoalkyl, O-aminoacid, O-aminoacyl, heterocycloalkyl, heterocycloalkaryl, aminoalkylamino, poly-alkylamino, substituted silyl, or a group having Formula I, and R1, R2 or R3 serves as points of attachment to the siNA molecule of the invention.

In another embodiment, the invention features a compound having Formula VII, wherein R1 and R2 are hydroxyl (OH) groups, n=1, and R3 comprises 0 and is the point of attachment to the 3′-end, the 5′-end, or both of the 3′ and 5′-ends of one or both strands of a double-stranded siNA molecule of the invention or to a single-stranded siNA molecule of the invention. This modification is referred to herein as “glyceryl” (for example modification 6 in FIG. 10).

In another embodiment, a chemically modified nucleoside or non-nucleoside (e.g. a moiety having any of Formula V, VI or VII) of the invention is at the 3′-end, the 5′-end, or both of the 3′ and 5′-ends of an siNA molecule of the invention. For example, chemically modified nucleoside or non-nucleoside (e.g., a moiety having Formula V, VI or VII) can be present at the 3′-end, the 5′-end, or both of the 3′ and 5′-ends of the antisense strand, the sense strand, or both antisense and sense strands of the siNA molecule. In one embodiment, the chemically modified nucleoside or non-nucleoside (e.g., a moiety having Formula V, VI or VII) is present at the 5′-end and 3′-end of the sense strand and the 3′-end of the antisense strand of a double-stranded siNA molecule of the invention. In one embodiment, the chemically modified nucleoside or non-nucleoside (e.g., a moiety having Formula V, VI or VII) is present at the terminal position of the 5′-end and 3′-end of the sense strand and the 3′-end of the antisense strand of a double-stranded siNA molecule of the invention. In one embodiment, the chemically modified nucleoside or non-nucleoside (e.g., a moiety having Formula V, VI or VII) is present at the two terminal positions of the 5′-end and 3′-end of the sense strand and the 3′-end of the antisense strand of a double-stranded siNA molecule of the invention. In one embodiment, the chemically modified nucleoside or non-nucleoside (e.g., a moiety having Formula V, VI or VII) is present at the penultimate position of the 5′-end and 3′-end of the sense strand and the 3′-end of the antisense strand of a double-stranded siNA molecule of the invention. In addition, a moiety having Formula VII can be present at the 3′-end or the 5′-end of a hairpin siNA molecule as described herein.

In another embodiment, an siNA molecule of the invention comprises an abasic residue having Formula V or VI, wherein the abasic residue having Formula VI or VI is connected to the siNA construct in a 3′-3′,3′-2′,2′-3′, or 5′-5′ configuration, such as at the 3′-end, the 5′-end, or both of the 3′ and 5′-ends of one or both siNA strands.

In one embodiment, an siNA molecule of the invention comprises one or more (e.g., about 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, or more) locked nucleic acid (LNA) nucleotides, for example, at the 5′-end, the 3′-end, both of the 5′ and 3′-ends, or any combination thereof, of the siNA molecule.

In another embodiment, an siNA molecule of the invention comprises one or more (e.g., about 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, or more) acyclic nucleotides, for example, at the 5′-end, the 3′-end, both of the 5′ and 3′-ends, or any combination thereof, of the siNA molecule.

In one embodiment, the invention features a chemically modified short interfering nucleic acid (siNA) molecule of the invention comprising a sense region, wherein any (e.g., one or more or all) pyrimidine nucleotides present in the sense region are 2′-deoxy-2′-fluoro pyrimidine nucleotides (e.g., wherein all pyrimidine nucleotides are 2′-deoxy-2′-fluoro pyrimidine nucleotides or alternately a plurality of pyrimidine nucleotides are 2′-deoxy-2′-fluoro pyrimidine nucleotides), and wherein any (e.g., one or more or all) purine nucleotides present in the sense region are 2′-deoxy purine nucleotides (e.g., wherein all purine nucleotides are 2′-deoxy purine nucleotides or alternately a plurality of purine nucleotides are 2′-deoxy purine nucleotides).

In one embodiment, the invention features a chemically modified short interfering nucleic acid (siNA) molecule of the invention comprising a sense region, wherein any (e.g., one or more or all) pyrimidine nucleotides present in the sense region are 2′-deoxy-2′-fluoro pyrimidine nucleotides (e.g., wherein all pyrimidine nucleotides are 2′-deoxy-2′-fluoro pyrimidine nucleotides or alternately a plurality of pyrimidine nucleotides are 2′-deoxy-2′-fluoro pyrimidine nucleotides), and wherein any (e.g., one or more or all) purine nucleotides present in the sense region are 2′-deoxy purine nucleotides (e.g., wherein all purine nucleotides are 2′-deoxy purine nucleotides or alternately a plurality of purine nucleotides are 2′-deoxy purine nucleotides), wherein any nucleotides comprising a 3′-terminal nucleotide overhang that are present in said sense region are 2′-deoxy nucleotides.

In one embodiment, the invention features a chemically modified short interfering nucleic acid (siNA) molecule of the invention comprising a sense region, wherein any (e.g., one or more or all) pyrimidine nucleotides present in the sense region are 2′-deoxy-2′-fluoro pyrimidine nucleotides (e.g., wherein all pyrimidine nucleotides are 2′-deoxy-2′-fluoro pyrimidine nucleotides or alternately a plurality of pyrimidine nucleotides are 2′-deoxy-2′-fluoro pyrimidine nucleotides), and wherein any (e.g., one or more or all) purine nucleotides present in the sense region are 2′-O-methyl purine nucleotides (e.g., wherein all purine nucleotides are 2′-O-methyl purine nucleotides or alternately a plurality of purine nucleotides are 2′-O-methyl purine nucleotides).

In one embodiment, the invention features a chemically modified short interfering nucleic acid (siNA) molecule of the invention comprising a sense region, wherein any (e.g., one or more or all) pyrimidine nucleotides present in the sense region are 2′-deoxy-2′-fluoro pyrimidine nucleotides (e.g., wherein all pyrimidine nucleotides are 2′-deoxy-2′-fluoro pyrimidine nucleotides or alternately a plurality of pyrimidine nucleotides are 2′-deoxy-2′-fluoro pyrimidine nucleotides), wherein any (e.g., one or more or all) purine nucleotides present in the sense region are 2′-O-methyl purine nucleotides (e.g., wherein all purine nucleotides are 2′-O-methyl purine nucleotides or alternately a plurality of purine nucleotides are 2′-O-methyl purine nucleotides), and wherein any nucleotides comprising a 3′-terminal nucleotide overhang that are present in said sense region are 2′-deoxy nucleotides.

In one embodiment, the invention features a chemically modified short interfering nucleic acid (siNA) molecule of the invention comprising an antisense region, wherein any (e.g., one or more or all) pyrimidine nucleotides present in the antisense region are 2′-deoxy-2′-fluoro pyrimidine nucleotides (e.g., wherein all pyrimidine nucleotides are 2′-deoxy-2′-fluoro pyrimidine nucleotides or alternately a plurality of pyrimidine nucleotides are 2′-deoxy-2′-fluoro pyrimidine nucleotides), and wherein any (e.g., one or more or all) purine nucleotides present in the antisense region are 2′-O-methyl purine nucleotides (e.g., wherein all purine nucleotides are 2′-O-methyl purine nucleotides or alternately a plurality of purine nucleotides are 2′-O-methyl purine nucleotides).

In one embodiment, the invention features a chemically modified short interfering nucleic acid (siNA) molecule of the invention comprising an antisense region, wherein any (e.g., one or more or all) pyrimidine nucleotides present in the antisense region are 2′-deoxy-2′-fluoro pyrimidine nucleotides (e.g., wherein all pyrimidine nucleotides are 2′-deoxy-2′-fluoro pyrimidine nucleotides or alternately a plurality of pyrimidine nucleotides are 2′-deoxy-2′-fluoro pyrimidine nucleotides), wherein any (e.g., one or more or all) purine nucleotides present in the antisense region are 2′-O-methyl purine nucleotides (e.g., wherein all purine nucleotides are 2′-O-methyl purine nucleotides or alternately a plurality of purine nucleotides are 2′-O-methyl purine nucleotides), and wherein any nucleotides comprising a 3′-terminal nucleotide overhang that are present in said antisense region are 2′-deoxy nucleotides.

In one embodiment, the invention features a chemically modified short interfering nucleic acid (siNA) molecule of the invention comprising an antisense region, wherein any (e.g., one or more or all) pyrimidine nucleotides present in the antisense region are 2′-deoxy-2′-fluoro pyrimidine nucleotides (e.g., wherein all pyrimidine nucleotides are 2′-deoxy-2′-fluoro pyrimidine nucleotides or alternately a plurality of pyrimidine nucleotides are 2′-deoxy-2′-fluoro pyrimidine nucleotides), and wherein any (e.g., one or more or all) purine nucleotides present in the antisense region are 2′-deoxy purine nucleotides (e.g., wherein all purine nucleotides are 2′-deoxy purine nucleotides or alternately a plurality of purine nucleotides are 2′-deoxy purine nucleotides).

In one embodiment, the invention features a chemically modified short interfering nucleic acid (siNA) molecule of the invention comprising an antisense region, wherein any (e.g., one or more or all) pyrimidine nucleotides present in the antisense region are 2′-deoxy-2′-fluoro pyrimidine nucleotides (e.g., wherein all pyrimidine nucleotides are 2′-deoxy-2′-fluoro pyrimidine nucleotides or alternately a plurality of pyrimidine nucleotides are 2′-deoxy-2′-fluoro pyrimidine nucleotides), and wherein any (e.g., one or more or all) purine nucleotides present in the antisense region are 2′-O-methyl purine nucleotides (e.g., wherein all purine nucleotides are 2′-O-methyl purine nucleotides or alternately a plurality of purine nucleotides are 2′-O-methyl purine nucleotides).

In one embodiment, the invention features a chemically modified short interfering nucleic acid (siNA) molecule of the invention capable of mediating RNA interference (RNAi) against SCD inside a cell or reconstituted in vitro system comprising a sense region, wherein one or more pyrimidine nucleotides present in the sense region are 2′-deoxy-2′-fluoro pyrimidine nucleotides (e.g., wherein all pyrimidine nucleotides are 2′-deoxy-2′-fluoro pyrimidine nucleotides or alternately a plurality of pyrimidine nucleotides are 2′-deoxy-2′-fluoro pyrimidine nucleotides), and one or more purine nucleotides present in the sense region are 2′-deoxy purine nucleotides (e.g., wherein all purine nucleotides are 2′-deoxy purine nucleotides or alternately a plurality of purine nucleotides are 2′-deoxy purine nucleotides), and an antisense region, wherein one or more pyrimidine nucleotides present in the antisense region are 2′-deoxy-2′-fluoro pyrimidine nucleotides (e.g., wherein all pyrimidine nucleotides are 2′-deoxy-2′-fluoro pyrimidine nucleotides or alternately a plurality of pyrimidine nucleotides are 2′-deoxy-2′-fluoro pyrimidine nucleotides), and one or more purine nucleotides present in the antisense region are 2′-O-methyl purine nucleotides (e.g., wherein all purine nucleotides are 2′-O-methyl purine nucleotides or alternately a plurality of purine nucleotides are 2′-O-methyl purine nucleotides). The sense region and/or the antisense region can have a terminal cap modification, such as any modification described herein or shown in FIG. 10, that is optionally present at the 3′-end, the 5′-end, or both of the 3′ and 5′-ends of the sense and/or antisense sequence. The sense and/or antisense region can optionally further comprise a 3′-terminal nucleotide overhang having about 1 to about 4 (e.g., about 1, 2, 3, or 4) 2′-deoxynucleotides. The overhang nucleotides can further comprise one or more (e.g., about 1, 2, 3, 4 or more) phosphorothioate, phosphonoacetate, and/or thiophosphonoacetate internucleotide linkages. Non-limiting examples of these chemically modified siNAs are shown in FIGS. 4 and 5 and Tables III and IV herein. In any of these described embodiments, the purine nucleotides present in the sense region are alternatively 2′-O-methyl purine nucleotides (e.g., wherein all purine nucleotides are 2′-O-methyl purine nucleotides or alternately a plurality of purine nucleotides are 2′-O-methyl purine nucleotides) and one or more purine nucleotides present in the antisense region are 2′-O-methyl purine nucleotides (e.g., wherein all purine nucleotides are 2′-O-methyl purine nucleotides or alternately a plurality of purine nucleotides are 2′-O-methyl purine nucleotides). Also, in any of these embodiments, one or more purine nucleotides present in the sense region are alternatively purine ribonucleotides (e.g., wherein all purine nucleotides are purine ribonucleotides or alternately a plurality of purine nucleotides are purine ribonucleotides) and any purine nucleotides present in the antisense region are 2′-O-methyl purine nucleotides (e.g., wherein all purine nucleotides are 2′-O-methyl purine nucleotides or alternately a plurality of purine nucleotides are 2′-O-methyl purine nucleotides). Additionally, in any of these embodiments, one or more purine nucleotides present in the sense region and/or present in the antisense region are alternatively selected from the group consisting of 2′-deoxy nucleotides, locked nucleic acid (LNA) nucleotides, 2′-methoxyethyl nucleotides, 4′-thionucleotides, and 2′-O-methyl nucleotides (e.g., wherein all purine nucleotides are selected from the group consisting of 2′-deoxy nucleotides, locked nucleic acid (LNA) nucleotides, 2′-methoxyethyl nucleotides, 4′-thionucleotides, and 2′-O-methyl nucleotides or alternately a plurality of purine nucleotides are selected from the group consisting of 2′-deoxy nucleotides, locked nucleic acid (LNA) nucleotides, 2′-methoxyethyl nucleotides, 4′-thionucleotides, and 2′-O-methyl nucleotides).

In another embodiment, any modified nucleotides present in the siNA molecules of the invention, preferably in the antisense strand of the siNA molecules of the invention, but also optionally in the sense and/or both antisense and sense strands, comprise modified nucleotides having properties or characteristics similar to naturally occurring ribonucleotides. For example, the invention features siNA molecules including modified nucleotides having a Northern conformation (e.g., Northern pseudorotation cycle, see for example Saenger, Principles of Nucleic Acid Structure, Springer-Verlag ed., 1984). As such, chemically modified nucleotides present in the siNA molecules of the invention, preferably in the antisense strand of the siNA molecules of the invention, but also optionally in the sense and/or both antisense and sense strands, are resistant to nuclease degradation while at the same time maintaining the capacity to mediate RNAi. Non-limiting examples of nucleotides having a Northern configuration include locked nucleic acid (LNA) nucleotides (e.g., 2′-O, 4′-C-methylene-(D-ribofuranosyl) nucleotides); 2′-methoxyethoxy (MOE) nucleotides; 2′-methyl-thio-ethyl, 2′-deoxy-2′-fluoro nucleotides, 2′-deoxy-2′-chloro nucleotides, 2′-azido nucleotides, and 2′-O-methyl nucleotides.

In one embodiment, the sense strand of a double-stranded siNA molecule of the invention comprises a terminal cap moiety, (see for example FIG. 10) such as an inverted deoxyabasic moiety, at the 3′-end, 5′-end, or both 3′ and 5′-ends of the sense strand.

In one embodiment, the invention features a chemically modified short interfering nucleic acid molecule (siNA) capable of mediating RNA interference (RNAi) against SCD inside a cell or reconstituted in vitro system, wherein the chemical modification comprises a conjugate covalently attached to the chemically modified siNA molecule. Non-limiting examples of conjugates contemplated by the invention include conjugates and ligands described in Vargeese et al., U.S. Ser. No. 10/427,160, filed Apr. 30, 2003, incorporated by reference herein in its entirety, including the drawings. In another embodiment, the conjugate is covalently attached to the chemically modified siNA molecule via a biodegradable linker. In one embodiment, the conjugate molecule is attached at the 3′-end of either the sense strand, the antisense strand, or both strands of the chemically modified siNA molecule. In another embodiment, the conjugate molecule is attached at the 5′-end of either the sense strand, the antisense strand, or both strands of the chemically modified siNA molecule. In yet another embodiment, the conjugate molecule is attached both the 3′-end and 5′-end of either the sense strand, the antisense strand, or both strands of the chemically modified siNA molecule, or any combination thereof. In one embodiment, a conjugate molecule of the invention comprises a molecule that facilitates delivery of a chemically modified siNA molecule into a biological system, such as a cell. In another embodiment, the conjugate molecule attached to the chemically modified siNA molecule is a polyethylene glycol, human serum albumin, or a ligand for a cellular receptor that can mediate cellular uptake. Examples of specific conjugate molecules contemplated by the instant invention that can be attached to chemically modified siNA molecules are described in Vargeese et al., U.S. Ser. No. 10/201,394, filed Jul. 22, 2002 incorporated by reference herein. The type of conjugates used and the extent of conjugation of siNA molecules of the invention can be evaluated for improved pharmacokinetic profiles, bioavailability, and/or stability of siNA constructs while at the same time maintaining the ability of the siNA to mediate RNAi activity. As such, one skilled in the art can screen siNA constructs that are modified with various conjugates to determine whether the siNA conjugate complex possesses improved properties while maintaining the ability to mediate RNAi, for example in animal models as are generally known in the art.

In one embodiment, the invention features a short interfering nucleic acid (siNA) molecule of the invention, wherein the siNA further comprises a nucleotide, non-nucleotide, or mixed nucleotide/non-nucleotide linker that joins the sense region of the siNA to the antisense region of the siNA. In one embodiment, a nucleotide linker of the invention can be a linker of ≧2 nucleotides in length, for example about 3, 4, 5, 6, 7, 8, 9, or 10 nucleotides in length. In another embodiment, the nucleotide linker can be a nucleic acid aptamer. By “aptamer” or “nucleic acid aptamer” as used herein is meant a nucleic acid molecule that binds specifically to a target molecule wherein the nucleic acid molecule has a sequence that comprises a sequence recognized by the target molecule in its natural setting. Alternately, an aptamer can be a nucleic acid molecule that binds to a target molecule where the target molecule does not naturally bind to a nucleic acid. The target molecule can be any molecule of interest. For example, the aptamer can be used to bind to a ligand-binding domain of a protein, thereby preventing interaction of the naturally occurring ligand with the protein. This is a non-limiting example and those in the art will recognize that other embodiments can be readily generated using techniques generally known in the art. (See, for example, Gold et al., 1995, Annu. Rev. Biochem., 64, 763; Brody and Gold, 2000, J. Biotechnol., 74, 5; Sun, 2000, Curr. Opin. Mol. Ther., 2, 100; Kusser, 2000, J. Biotechnol., 74, 27; Hermann and Patel, 2000, Science, 287, 820; and Jayasena, 1999, Clinical Chemistry, 45, 1628.)

In yet another embodiment, a non-nucleotide linker of the invention comprises abasic nucleotide, polyether, polyamine, polyamide, peptide, carbohydrate, lipid, polyhydrocarbon, or other polymeric compounds (e.g. polyethylene glycols such as those having between 2 and 100 ethylene glycol units). Specific examples include those described by Seela and Kaiser, Nucleic Acids Res. 1990, 18:6353 and Nucleic Acids Res. 1987, 15:3113; Cload and Schepartz, J. Am. Chem. Soc. 1991, 113:6324; Richardson and Schepartz, J. Am. Chem. Soc. 1991, 113:5109; Ma et al., Nucleic Acids Res. 1993, 21:2585 and Biochemistry 1993, 32:1751; Durand et al., Nucleic Acids Res. 1990, 18:6353; McCurdy et al., Nucleosides & Nucleotides 1991, 10:287; Jschke et al., Tetrahedron Lett. 1993, 34:301; Ono et al., Biochemistry 1991, 30:9914; Arnold et al., International Publication No. WO 89/02439; Usman et al., International Publication No. WO 95/06731; Dudycz et al., International Publication No. WO 95/11910 and Ferentz and Verdine, J. Am. Chem. Soc. 1991, 113:4000, all hereby incorporated by reference herein. A “non-nucleotide” further means any group or compound that can be incorporated into a nucleic acid chain in the place of one or more nucleotide units, including either sugar and/or phosphate substitutions, and allows the remaining bases to exhibit their enzymatic activity. The group or compound can be abasic in that it does not contain a commonly recognized nucleotide base, such as adenosine, guanine; cytosine, uracil or thymine, for example at the C1 position of the sugar.

In one embodiment, the invention features a short interfering nucleic acid (siNA) molecule capable of mediating RNA interference (RNAi) inside a cell or reconstituted in vitro system, wherein one or both strands of the siNA molecule that are assembled from two separate oligonucleotides do not comprise any ribonucleotides. For example, an siNA molecule can be assembled from a single oligonucleotide where the sense and antisense regions of the siNA comprise separate oligonucleotides that do not have any ribonucleotides (e.g., nucleotides having a 2′-OH group) present in the oligonucleotides. In another example, an siNA molecule can be assembled from a single oligonucleotide where the sense and antisense regions of the siNA are linked or circularized by a nucleotide or non-nucleotide linker as described herein, wherein the oligonucleotide does not have any ribonucleotides (e.g., nucleotides having a 2′-OH group) present in the oligonucleotide. Applicant has surprisingly found that the presence of ribonucleotides (e.g., nucleotides having a 2′-hydroxyl group) within the siNA molecule is not required or essential to support RNAi activity. As such, in one embodiment, all positions within the siNA can include chemically modified nucleotides and/or non-nucleotides such as nucleotides and or non-nucleotides having Formula I, II, III, IV, V, VI, or VII or any combination thereof to the extent that the ability of the siNA molecule to support RNAi activity in a cell is maintained.

In one embodiment, an siNA molecule of the invention is a single-stranded siNA molecule that mediates RNAi activity in a cell or reconstituted in vitro system comprising a single-stranded polynucleotide having complementarity to a target nucleic acid sequence. In another embodiment, the single-stranded siNA molecule of the invention comprises a 5′-terminal phosphate group. In another embodiment, the single-stranded siNA molecule of the invention comprises a 5′-terminal phosphate group and a 3′-terminal phosphate group (e.g., a 2′,3′-cyclic phosphate). In another embodiment, the single-stranded siNA molecule of the invention comprises about 15 to about 30 (e.g., about 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, or 30) nucleotides. In yet another embodiment, the single-stranded siNA molecule of the invention comprises one or more chemically modified nucleotides or non-nucleotides described herein. For example, all the positions within the siNA molecule can include chemically modified nucleotides such as nucleotides having any of Formulae I-VII, or any combination thereof to the extent that the ability of the siNA molecule to support RNAi activity in a cell is maintained.

In one embodiment, an siNA molecule of the invention is a single-stranded siNA molecule that mediates RNAi activity in a cell or reconstituted in vitro system comprising a single-stranded polynucleotide having complementarity to a target nucleic acid sequence, wherein one or more pyrimidine nucleotides present in the siNA are 2′-deoxy-2′-fluoro pyrimidine nucleotides (e.g., wherein all pyrimidine nucleotides are 2′-deoxy-2′-fluoro pyrimidine nucleotides or alternately a plurality of pyrimidine nucleotides are 2′-deoxy-2′-fluoro pyrimidine nucleotides), and wherein any purine nucleotides present in the antisense region are 2′-O-methyl purine nucleotides (e.g., wherein all purine nucleotides are 2′-O-methyl purine nucleotides or alternately a plurality of purine nucleotides are 2′-O-methyl purine nucleotides), and a terminal cap modification, such as any modification described herein or shown in FIG. 10, that is optionally present at the 3′-end and/or the 5′-end. The siNA optionally further comprises about 1 to about 4 or more (e.g., about 1, 2, 3, 4 or more) terminal 2′-deoxynucleotides at the 3′-end of the siNA molecule, wherein the terminal nucleotides can further comprise one or more (e.g., 1, 2, 3, 4 or more) phosphorothioate, phosphonoacetate, and/or thiophosphonoacetate internucleotide linkages, and wherein the siNA optionally further comprises a terminal phosphate group, such as a 5′-terminal phosphate group. In any of these embodiments, any purine nucleotides present in the antisense region are alternatively 2′-deoxy purine nucleotides (e.g., wherein all purine nucleotides are 2′-deoxy purine nucleotides or alternately a plurality of purine nucleotides are 2′-deoxy purine nucleotides). Also, in any of these embodiments, any purine nucleotides present in the siNA (i.e., purine nucleotides present in the sense and/or antisense region) can alternatively be locked nucleic acid (LNA) nucleotides (e.g., wherein all purine nucleotides are LNA nucleotides or alternately a plurality of purine nucleotides are LNA nucleotides). Also, in any of these embodiments, any purine nucleotides present in the siNA are alternatively 2′-methoxyethyl purine nucleotides (e.g., wherein all purine nucleotides are 2′-methoxyethyl purine nucleotides or alternately a plurality of purine nucleotides are 2′-methoxyethyl purine nucleotides). In another embodiment, any modified nucleotides present in the single-stranded siNA molecules of the invention comprise modified nucleotides having properties or characteristics similar to naturally occurring ribonucleotides. For example, the invention features siNA molecules including modified nucleotides having a Northern conformation (e.g., Northern pseudorotation cycle, see for example Saenger, Principles of Nucleic Acid Structure, Springer-Verlag ed., 1984). As such, chemically modified nucleotides present in the single-stranded siNA molecules of the invention are preferably resistant to nuclease degradation while at the same time maintaining the capacity to mediate RNAi.

In one embodiment, an siNA molecule of the invention comprises chemically modified nucleotides or non-nucleotides (e.g., having any of Formulae I-VII, such as 2′-deoxy, 2′-deoxy-2′-fluoro, or 2′-O-methyl nucleotides) at alternating positions within one or more strands or regions of the siNA molecule. For example, such chemical modifications can be introduced at every other position of a RNA based siNA molecule, starting at either the first or second nucleotide from the 3′-end or 5′-end of the siNA. In a non-limiting example, a double-stranded siNA molecule of the invention in which each strand of the siNA is 21 nucleotides in length is featured wherein positions 1, 3, 5, 7, 9, 11, 13, 15, 17, 19 and 21 of each strand are chemically modified (e.g., with compounds having any of Formulae I-VII, such as such as 2′-deoxy, 2′-deoxy-2′-fluoro, or 2′-O-methyl nucleotides). In another non-limiting example, a double-stranded siNA molecule of the invention in which each strand of the siNA is 21 nucleotides in length is featured wherein positions 2, 4, 6, 8, 10, 12, 14, 16, 18, and 20 of each strand are chemically modified (e.g., with compounds having any of Formulae I-VII, such as such as 2′-deoxy, 2′-deoxy-2′-fluoro, or 2′-O-methyl nucleotides). Such siNA molecules can further comprise terminal cap moieties and/or backbone modifications as described herein.

In one embodiment, the invention features a method for modulating the expression of a SCD gene within a cell comprising: (a) synthesizing an siNA molecule of the invention, which can be chemically modified, wherein one of the siNA strands comprises a sequence complementary to RNA of the SCD gene; and (b) introducing the siNA molecule into a cell under conditions suitable to modulate the expression of the SCD gene in the cell.

In one embodiment, the invention features a method for modulating the expression of a SCD gene within a cell comprising: (a) synthesizing an siNA molecule of the invention, which can be chemically modified, wherein one of the siNA strands comprises a sequence complementary to RNA of the SCD gene and wherein the sense strand sequence of the siNA comprises a sequence identical or substantially similar to the sequence of the target RNA; and (b) introducing the siNA molecule into a cell under conditions suitable to modulate the expression of the SCD gene in the cell.

In another embodiment, the invention features a method for modulating the expression of more than one SCD gene within a cell comprising: (a) synthesizing siNA molecules of the invention, which can be chemically modified, wherein one of the siNA strands comprises a sequence complementary to RNA of the SCD genes; and (b) introducing the siNA molecules into a cell under conditions suitable to modulate the expression of the SCD genes in the cell.

In another embodiment, the invention features a method for modulating the expression of two or more SCD genes within a cell comprising: (a) synthesizing one or more siNA molecules of the invention, which can be chemically modified, wherein the siNA strands comprise sequences complementary to RNA of the SCD genes and wherein the sense strand sequences of the siNAs comprise sequences identical or substantially similar to the sequences of the target RNAs; and (b) introducing the siNA molecules into a cell under conditions suitable to modulate the expression of the SCD genes in the cell.

In another embodiment, the invention features a method for modulating the expression of more than one SCD gene within a cell comprising: (a) synthesizing an siNA molecule of the invention, which can be chemically modified, wherein one of the siNA strands comprises a sequence complementary to RNA of the SCD gene and wherein the sense strand sequence of the siNA comprises a sequence identical or substantially similar to the sequences of the target RNAs; and (b) introducing the siNA molecule into a cell under conditions suitable to modulate the expression of the SCD genes in the cell.

In one embodiment, siNA molecules of the invention are used as reagents in ex vivo applications. For example, siNA reagents are introduced into tissue or cells that are transplanted into a subject for therapeutic effect. The cells and/or tissue can be derived from an organism or subject that later receives the explant, or can be derived from another organism or subject prior to transplantation. The siNA molecules can be used to modulate the expression of one or more genes in the cells or tissue, such that the cells or tissue obtain a desired phenotype or are able to perform a function when transplanted in vivo. In one embodiment, certain target cells from a patient are extracted. These extracted cells are contacted with siNAs targeting a specific nucleotide sequence within the cells under conditions suitable for uptake of the siNAs by these cells (e.g. using delivery reagents such as cationic lipids, liposomes and the like or using techniques such as electroporation to facilitate the delivery of siNAs into cells). The cells are then reintroduced back into the same patient or other patients. In one embodiment, the invention features a method of modulating the expression of a SCD gene in a tissue explant comprising: (a) synthesizing an siNA molecule of the invention, which can be chemically modified, wherein one of the siNA strands comprises a sequence complementary to RNA of the SCD gene; and (b) introducing the siNA molecule into a cell of the tissue explant derived from a particular organism under conditions suitable to modulate the expression of the SCD gene in the tissue explant. In another embodiment, the method further comprises introducing the tissue explant back into the organism the tissue was derived from or into another organism under conditions suitable to modulate the expression of the SCD gene in that organism.

In one embodiment, the invention features a method of modulating the expression of a SCD gene in a tissue explant comprising: (a) synthesizing an siNA molecule of the invention, which can be chemically modified, wherein one of the siNA strands comprises a sequence complementary to RNA of the SCD gene and wherein the sense strand sequence of the siNA comprises a sequence identical or substantially similar to the sequence of the target RNA; and (b) introducing the siNA molecule into a cell of the tissue explant derived from a particular organism under conditions suitable to modulate the expression of the SCD gene in the tissue explant. In another embodiment, the method further comprises introducing the tissue explant back into the organism the tissue was derived from or into another organism under conditions suitable to modulate the expression of the SCD gene in that organism.

In another embodiment, the invention features a method of modulating the expression of more than one SCD gene in a tissue explant comprising: (a) synthesizing siNA molecules of the invention, which can be chemically modified, wherein one of the siNA strands comprises a sequence complementary to RNA of the SCD genes; and (b) introducing the siNA molecules into a cell of the tissue explant derived from a particular organism under conditions suitable to modulate the expression of the SCD genes in the tissue explant. In another embodiment, the method further comprises introducing the tissue explant back into the organism the tissue was derived from or into another organism under conditions suitable to modulate the expression of the SCD genes in that organism.

In one embodiment, the invention features a method of modulating the expression of a SCD gene in a subject or organism comprising: (a) synthesizing an siNA molecule of the invention, which can be chemically modified, wherein one of the siNA strands comprises a sequence complementary to RNA of the SCD gene; and (b) introducing the siNA molecule into the subject or organism under conditions suitable to modulate the expression of the SCD gene in the subject or organism. The level of SCD protein or RNA can be determined using various methods well-known in the art.

In another embodiment, the invention features a method of modulating the expression of more than one SCD gene in a subject or organism comprising: (a) synthesizing siNA molecules of the invention, which can be chemically modified, wherein one of the siNA strands comprises a sequence complementary to RNA of the SCD genes; and (b) introducing the siNA molecules into the subject or organism under conditions suitable to modulate the expression of the SCD genes in the subject or organism. The level of SCD protein or RNA can be determined as is known in the art.

In one embodiment, the invention features a method for modulating the expression of a SCD gene within a cell comprising: (a) synthesizing an siNA molecule of the invention, which can be chemically modified, wherein the siNA comprises a single-stranded sequence having complementarity to RNA of the SCD gene; and (b) introducing the siNA molecule into a cell under conditions suitable to modulate the expression of the SCD gene in the cell.

In another embodiment, the invention features a method for modulating the expression of more than one SCD gene within a cell comprising: (a) synthesizing siNA molecules of the invention, which can be chemically modified, wherein the siNA comprises a single-stranded sequence having complementarity to RNA of the SCD gene; and (b) contacting the cell in vitro or in vivo with the siNA molecule under conditions suitable to modulate the expression of the SCD genes in the cell.

In one embodiment, the invention features a method of modulating the expression of a SCD gene in a tissue explant comprising: (a) synthesizing an siNA molecule of the invention, which can be chemically modified, wherein the siNA comprises a single-stranded sequence having complementarity to RNA of the SCD gene; and (b) contacting a cell of the tissue explant derived from a particular subject or organism with the siNA molecule under conditions suitable to modulate the expression of the SCD gene in the tissue explant. In another embodiment, the method further comprises introducing the tissue explant back into the subject or organism the tissue was derived from or into another subject or organism under conditions suitable to modulate the expression of the SCD gene in that subject or organism.

In another embodiment, the invention features a method of modulating the expression of more than one SCD gene in a tissue explant comprising: (a) synthesizing siNA molecules of the invention, which can be chemically modified, wherein the siNA comprises a single-stranded sequence having complementarity to RNA of the SCD gene; and (b) introducing the siNA molecules into a cell of the tissue explant derived from a particular subject or organism under conditions suitable to modulate the expression of the SCD genes in the tissue explant. In another embodiment, the method further comprises introducing the tissue explant back into the subject or organism the tissue was derived from or into another subject or organism under conditions suitable to modulate the expression of the SCD genes in that subject or organism.

In one embodiment, the invention features a method of modulating the expression of a SCD gene in a subject or organism comprising: (a) synthesizing an siNA molecule of the invention, which can be chemically modified, wherein the siNA comprises a single-stranded sequence having complementarity to RNA of the SCD gene; and (b) introducing the siNA molecule into the subject or organism under conditions suitable to modulate the expression of the SCD gene in the subject or organism.

In another embodiment, the invention features a method of modulating the expression of more than one SCD gene in a subject or organism comprising: (a) synthesizing siNA molecules of the invention, which can be chemically modified, wherein the siNA comprises a single-stranded sequence having complementarity to RNA of the SCD gene; and (b) introducing the siNA molecules into the subject or organism under conditions suitable to modulate the expression of the SCD genes in the subject or organism.

In one embodiment, the invention features a method of modulating the expression of a SCD gene in a subject or organism comprising contacting the subject or organism with an siNA molecule of the invention under conditions suitable to modulate the expression of the SCD gene in the subject or organism.

In one embodiment, the invention features a method for treating or preventing diabetes (type I and/or type II) in a subject or organism comprising contacting the subject or organism with an siNA molecule of the invention under conditions suitable to modulate the expression of the SCD gene in the subject or organism.

In one embodiment, the invention features a method for treating or preventing atherosclerosis in a subject or organism comprising contacting the subject or organism with an siNA molecule of the invention under conditions suitable to modulate the expression of the SCD gene in the subject or organism.

In one embodiment, the invention features a method for treating or preventing cancer in a subject or organism comprising contacting the subject or organism with an siNA molecule of the invention under conditions suitable to modulate the expression of the SCD gene in the subject or organism.

In one embodiment, the invention features a method for treating or preventing obesity in a subject or organism comprising contacting the subject or organism with an siNA molecule of the invention under conditions suitable to modulate the expression of the SCD gene in the subject or organism.

In one embodiment, the invention features a method for inducing weight loss in a subject or organism comprising contacting the subject or organism with an siNA molecule of the invention under conditions suitable to modulate the expression of the SCD gene in the subject or organism.

In one embodiment, the invention features a method for treating or preventing a viral infection in a subject or organism comprising contacting the subject or organism with an siNA molecule of the invention under conditions suitable to modulate the expression of the SCD gene in the subject or organism.

In another embodiment, the invention features a method of modulating the expression of more than one SCD genes in a subject or organism comprising contacting the subject or organism with one or more siNA molecules of the invention under conditions suitable to modulate the expression of the SCD genes in the subject or organism.

The siNA molecules of the invention can be designed to down regulate or inhibit target (e.g., SCD) gene expression through RNAi targeting of a variety of RNA molecules. In one embodiment, the siNA molecules of the invention are used to target various RNAs corresponding to a target gene. Non-limiting examples of such RNAs include messenger RNA (mRNA), alternate RNA splice variants of target gene(s), post-transcriptionally modified RNA of target gene(s), pre-mRNA of target gene(s), and/or RNA templates. If alternate splicing produces a family of transcripts that are distinguished by usage of appropriate exons, the instant invention can be used to inhibit gene expression through the appropriate exons to specifically inhibit or to distinguish among the functions of gene family members. For example, a protein that contains an alternatively spliced transmembrane domain can be expressed in both membrane bound and secreted forms. Use of the invention to target the exon containing the transmembrane domain can be used to determine the functional consequences of pharmaceutical targeting of membrane bound as opposed to the secreted form of the protein. Non-limiting examples of applications of the invention relating to targeting these RNA molecules include therapeutic pharmaceutical applications, pharmaceutical discovery applications, molecular diagnostic and gene function applications, and gene mapping, for example using single nucleotide polymorphism mapping with siNA molecules of the invention. Such applications can be implemented using known gene sequences or from partial sequences available from an expressed sequence tag (EST).

In another embodiment, the siNA molecules of the invention are used to target conserved sequences corresponding to a gene family or gene families such as SCD family genes. As such, siNA molecules targeting multiple SCD targets can provide increased therapeutic effect. In addition, siNA can be used to characterize pathways of gene function in a variety of applications. For example, the present invention can be used to inhibit the activity of target gene(s) in a pathway to determine the function of uncharacterized gene(s) in gene function analysis, mRNA function analysis, or translational analysis. The invention can be used to determine potential target gene pathways involved in various diseases and conditions toward pharmaceutical development. The invention can be used to understand pathways of gene expression involved in, for example diabetes (type I and/or type II), atherosclerosis, cancer, obesity, and viral infection.

In one embodiment, siNA molecule(s) and/or methods of the invention are used to down regulate the expression of gene(s) that encode RNA referred to by Genbank Accession Nos., for example, SCD genes encoding RNA sequence(s) referred to herein by Genbank Accession number, for example, Genbank Accession Nos. shown in Table I.

In one embodiment, the invention features a method comprising: (a) generating a library of siNA constructs having a predetermined complexity; and (b) assaying the siNA constructs of (a) above, under conditions suitable to determine RNAi target sites within the target RNA sequence. In one embodiment, the siNA molecules of (a) have strands of a fixed length, for example, about 23 nucleotides in length. In another embodiment, the siNA molecules of (a) are of differing length, for example having strands of about 15 to about 30 (e.g., about 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, or 30) nucleotides in length. In one embodiment, the assay can comprise a reconstituted in vitro siNA assay as described herein. In another embodiment, the assay can comprise a cell culture system in which target RNA is expressed. In another embodiment, fragments of target RNA are analyzed for detectable levels of cleavage, for example by gel electrophoresis, Northern blot analysis, or RNAse protection assays, to determine the most suitable target site(s) within the target RNA sequence. The target RNA sequence can be obtained as is known in the art, for example, by cloning and/or transcription for in vitro systems, and by cellular expression in in vivo systems.

In one embodiment, the invention features a method comprising: (a) generating a randomized library of siNA constructs having a predetermined complexity, such as of 4^(N), where N represents the number of base paired nucleotides in each of the siNA construct strands (e.g., for an siNA construct having 21 nucleotide sense and antisense strands with 19 base pairs, the complexity would be 4¹⁹); and (b) assaying the siNA constructs of (a) above, under conditions suitable to determine RNAi target sites within the target SCD RNA sequence. In another embodiment, the siNA molecules of (a) have strands of a fixed length, for example about 23 nucleotides in length. In yet another embodiment, the siNA molecules of (a) are of differing length, for example having strands of about 15 to about 30 (e.g., about 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, or 30) nucleotides in length. In one embodiment, the assay can comprise a reconstituted in vitro siNA assay as described in Example 6 herein. In another embodiment, the assay can comprise a cell culture system in which target RNA is expressed. In another embodiment, fragments of SCD RNA are analyzed for detectable levels of cleavage, for example, by gel electrophoresis, Northern blot analysis, or RNAse protection assays, to determine the most suitable target site(s) within the target SCD RNA sequence. The target SCD RNA sequence can be obtained as is known in the art, for example, by cloning and/or transcription for in vitro systems, and by cellular expression in in vivo systems.

In another embodiment, the invention features a method comprising: (a) analyzing the sequence of a RNA target encoded by a target gene; (b) synthesizing one or more sets of siNA molecules having sequence complementary to one or more regions of the RNA of (a); and (c) assaying the siNA molecules of (b) under conditions suitable to determine RNAi targets within the target RNA sequence. In one embodiment, the siNA molecules of (b) have strands of a fixed length, for example about 23 nucleotides in length. In another embodiment, the siNA molecules of (b) are of differing length, for example having strands of about 15 to about 30 (e.g., about 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, or 30) nucleotides in length. In one embodiment, the assay can comprise a reconstituted in vitro siNA assay as described herein. In another embodiment, the assay can comprise a cell culture system in which target RNA is expressed. Fragments of target RNA are analyzed for detectable levels of cleavage, for example by gel electrophoresis, Northern blot analysis, or RNAse protection assays, to determine the most suitable target site(s) within the target RNA sequence. The target RNA sequence can be obtained as is known in the art, for example, by cloning and/or transcription for in vitro systems, and by expression in in vivo systems.

By “target site” is meant a sequence within a target RNA that is “targeted” for cleavage mediated by an siNA construct which contains sequences within its antisense region that are complementary to the target sequence.

By “detectable level of cleavage” is meant cleavage of target RNA (and formation of cleaved product RNAs) to an extent sufficient to discern cleavage products above the background of RNAs produced by random degradation of the target RNA. Production of cleavage products from 1-5% of the target RNA is sufficient to detect above the background for most methods of detection.

In one embodiment, the invention features a composition comprising an siNA molecule of the invention, which can be chemically modified, in a pharmaceutically acceptable carrier or diluent. In another embodiment, the invention features a pharmaceutical composition comprising siNA molecules of the invention, which can be chemically modified, targeting one or more genes in a pharmaceutically acceptable carrier or diluent. In another embodiment, the invention features a method for diagnosing a disease or condition in a subject comprising administering to the subject a composition of the invention under conditions suitable for the diagnosis of the disease or condition in the subject. In another embodiment, the invention features a method for treating or preventing a disease or condition in a subject, comprising administering to the subject a composition of the invention under conditions suitable for the treatment or prevention of the disease or condition in the subject, alone or in conjunction with one or more other therapeutic compounds. In yet another embodiment, the invention features a method for treating or preventing diabetes (type I and/or type II), atherosclerosis, cancer, obesity, and viral infection in a subject or organism comprising administering to the subject a composition of the invention under conditions suitable for the treatment or prevention of diabetes (type I and/or type II), atherosclerosis, cancer, obesity, and viral infection in the subject or organism.

In another embodiment, the invention features a method for validating a SCD gene target, comprising: (a) synthesizing an siNA molecule of the invention, which can be chemically modified, wherein one of the siNA strands includes a sequence complementary to RNA of a SCD target gene; (b) introducing the siNA molecule into a cell, tissue, subject, or organism under conditions suitable for modulating expression of the SCD target gene in the cell, tissue, subject, or organism; and (c) determining the function of the gene by assaying for any phenotypic change in the cell, tissue, subject, or organism.

In another embodiment, the invention features a method for validating a SCD target comprising: (a) synthesizing an siNA molecule of the invention, which can be chemically modified, wherein one of the siNA strands includes a sequence complementary to RNA of a SCD target gene; (b) introducing the siNA molecule into a biological system under conditions suitable for modulating expression of the SCD target gene in the biological system; and (c) determining the function of the gene by assaying for any phenotypic change in the biological system.

By “biological system” is meant, material, in a purified or unpurified form, from biological sources, including but not limited to human or animal, wherein the system comprises the components required for RNAi activity. The term “biological system” includes, for example, a cell, tissue, subject, or organism, or extract thereof. The term biological system also includes reconstituted RNAi systems that can be used in an in vitro setting.

By “phenotypic change” is meant any detectable change to a cell that occurs in response to contact or treatment with a nucleic acid molecule of the invention (e.g., siNA). Such detectable changes include, but are not limited to, changes in shape, size, proliferation, motility, protein expression or RNA expression or other physical or chemical changes as can be assayed by methods known in the art. The detectable change can also include expression of reporter genes/molecules such as Green Florescent Protein (GFP) or various tags that are used to identify an expressed protein or any other cellular component that can be assayed.

In one embodiment, the invention features a kit containing an siNA molecule of the invention, which can be chemically modified, that can be used to modulate the expression of a SCD target gene in a biological system, including, for example, in a cell, tissue, subject, or organism. In another embodiment, the invention features a kit containing more than one siNA molecule of the invention, which can be chemically modified, that can be used to modulate the expression of more than one SCD target gene in a biological system, including, for example, in a cell, tissue, subject, or organism.

In one embodiment, the invention features a cell containing one or more siNA molecules of the invention, which can be chemically modified. In another embodiment, the cell containing an siNA molecule of the invention is a mammalian cell. In yet another embodiment, the cell containing an siNA molecule of the invention is a human cell.

In one embodiment, the synthesis of an siNA molecule of the invention, which can be chemically modified, comprises: (a) synthesis of two complementary strands of the siNA molecule; (b) annealing the two complementary strands together under conditions suitable to obtain a double-stranded siNA molecule. In another embodiment, synthesis of the two complementary strands of the siNA molecule is by solid phase oligonucleotide synthesis. In yet another embodiment, synthesis of the two complementary strands of the siNA molecule is by solid phase tandem oligonucleotide synthesis.

In one embodiment, the invention features a method for synthesizing an siNA duplex molecule comprising: (a) synthesizing a first oligonucleotide sequence strand of the siNA molecule, wherein the first oligonucleotide sequence strand comprises a cleavable linker molecule that can be used as a scaffold for the synthesis of the second oligonucleotide sequence strand of the siNA; (b) synthesizing the second oligonucleotide sequence strand of siNA on the scaffold of the first oligonucleotide sequence strand, wherein the second oligonucleotide sequence strand further comprises a chemical moiety than can be used to purify the siNA duplex; (c) cleaving the linker molecule of (a) under conditions suitable for the two siNA oligonucleotide strands to hybridize and form a stable duplex; and (d) purifying the siNA duplex utilizing the chemical moiety of the second oligonucleotide sequence strand. In one embodiment, cleavage of the linker molecule in (c) above takes place during deprotection of the oligonucleotide, for example, under hydrolysis conditions using an alkylamine base such as methylamine. In one embodiment, the method of synthesis comprises solid phase synthesis on a solid support such as controlled pore glass (CPG) or polystyrene, wherein the first sequence of (a) is synthesized on a cleavable linker, such as a succinyl linker, using the solid support as a scaffold. The cleavable linker in (a) used as a scaffold for synthesizing the second strand can comprise similar reactivity as the solid support derivatized linker, such that cleavage of the solid support derivatized linker and the cleavable linker of (a) takes place concomitantly. In another embodiment, the chemical moiety of (b) that can be used to isolate the attached oligonucleotide sequence comprises a trityl group, for example a dimethoxytrityl group, which can be employed in a trityl-on synthesis strategy as described herein. In yet another embodiment, the chemical moiety, such as a dimethoxytrityl group, is removed during purification, for example, using acidic conditions.

In a further embodiment, the method for siNA synthesis is a solution phase synthesis or hybrid phase synthesis wherein both strands of the siNA duplex are synthesized in tandem using a cleavable linker attached to the first sequence which acts a scaffold for synthesis of the second sequence. Cleavage of the linker under conditions suitable for hybridization of the separate siNA sequence strands results in formation of the double-stranded siNA molecule.

In another embodiment, the invention features a method for synthesizing an siNA duplex molecule comprising: (a) synthesizing one oligonucleotide sequence strand of the siNA molecule, wherein the sequence comprises a cleavable linker molecule that can be used as a scaffold for the synthesis of another oligonucleotide sequence; (b) synthesizing a second oligonucleotide sequence having complementarity to the first sequence strand on the scaffold of (a), wherein the second sequence comprises the other strand of the double-stranded siNA molecule and wherein the second sequence further comprises a chemical moiety than can be used to isolate the attached oligonucleotide sequence; (c) purifying the product of (b) utilizing the chemical moiety of the second oligonucleotide sequence strand under conditions suitable for isolating the full-length sequence comprising both siNA oligonucleotide strands connected by the cleavable linker and under conditions suitable for the two siNA oligonucleotide strands to hybridize and form a stable duplex. In one embodiment, cleavage of the linker molecule in (c) above takes place during deprotection of the oligonucleotide, for example, under hydrolysis conditions. In another embodiment, cleavage of the linker molecule in (c) above takes place after deprotection of the oligonucleotide. In another embodiment, the method of synthesis comprises solid phase synthesis on a solid support such as controlled pore glass (CPG) or polystyrene, wherein the first sequence of (a) is synthesized on a cleavable linker, such as a succinyl linker, using the solid support as a scaffold. The cleavable linker in (a) used as a scaffold for synthesizing the second strand can comprise similar reactivity or differing reactivity as the solid support derivatized linker, such that cleavage of the solid support derivatized linker and the cleavable linker of (a) takes place either concomitantly or sequentially. In one embodiment, the chemical moiety of (b) that can be used to isolate the attached oligonucleotide sequence comprises a trityl group, for example a dimethoxytrityl group.

In another embodiment, the invention features a method for making a double-stranded siNA molecule in a single synthetic process comprising: (a) synthesizing an oligonucleotide having a first and a second sequence, wherein the first sequence is complementary to the second sequence, and the first oligonucleotide sequence is linked to the second sequence via a cleavable linker, and wherein a terminal 5′-protecting group, for example, a 5′-O-dimethoxytrityl group (5′-O-DMT) remains on the oligonucleotide having the second sequence; (b) deprotecting the oligonucleotide whereby the deprotection results in the cleavage of the linker joining the two oligonucleotide sequences; and (c) purifying the product of (b) under conditions suitable for isolating the double-stranded siNA molecule, for example using a trityl-on synthesis strategy as described herein.

In another embodiment, the method of synthesis of siNA molecules of the invention comprises the teachings of Scaringe et al., U.S. Pat. Nos. 5,889,136; 6,008,400; and 6,111,086, incorporated by reference herein in their entirety.

In one embodiment, the invention features siNA constructs that mediate RNAi against SCD, wherein the siNA construct comprises one or more chemical modifications, for example, one or more chemical modifications having any of Formulae I-VII or any combination thereof that increases the nuclease resistance of the siNA construct.

In another embodiment, the invention features a method for generating siNA molecules with increased nuclease resistance comprising (a) introducing nucleotides having any of Formula I-VII or any combination thereof into an siNA molecule, and (b) assaying the siNA molecule of step (a) under conditions suitable for isolating siNA molecules having increased nuclease resistance.

In another embodiment, the invention features a method for generating siNA molecules with improved toxicologic profiles (e.g., have attenuated or no immunostimulatory properties) comprising (a) introducing nucleotides having any of Formula I-VII (e.g., siNA motifs referred to in Table IV) or any combination thereof into an siNA molecule, and (b) assaying the siNA molecule of step (a) under conditions suitable for isolating siNA molecules having improved toxicologic profiles.

In another embodiment, the invention features a method for generating siNA molecules that do not stimulate an interferon response (e.g., no interferon response or attenuated interferon response) in a cell, subject, or organism, comprising (a) introducing nucleotides having any of Formula I-VII (e.g., siNA motifs referred to in Table IV) or any combination thereof into an siNA molecule, and (b) assaying the siNA molecule of step (a) under conditions suitable for isolating siNA molecules that do not stimulate an interferon response.

By “improved toxicologic profile”, is meant that the chemically modified siNA construct exhibits decreased toxicity in a cell, subject, or organism compared to an unmodified siNA or siNA molecule having fewer modifications or modifications that are less effective in imparting improved toxicology. In a non-limiting example, siNA molecules with improved toxicologic profiles are associated with a decreased or attenuated immunostimulatory response in a cell, subject, or organism compared to an unmodified siNA or siNA molecule having fewer modifications or modifications that are less effective in imparting improved toxicology. In one embodiment, an siNA molecule with an improved toxicological profile comprises no ribonucleotides. In one embodiment, an siNA molecule with an improved toxicological profile comprises less than 5 ribonucleotides (e.g., 1, 2, 3, or 4 ribonucleotides). In one embodiment, an siNA molecule with an improved toxicological profile comprises Stab 7, Stab 8, Stab 11, Stab 12, Stab 13, Stab 16, Stab 17, Stab 18, Stab 19, Stab 20, Stab 23, Stab 24, Stab 25, Stab 26, Stab 27, Stab 28, Stab 29, Stab 30, Stab 31, Stab 32 or any combination thereof (see Table IV). In one embodiment, the level of immunostimulatory response associated with a given siNA molecule can be measured as is known in the art, for example by determining the level of PKR/interferon response, proliferation, B-cell activation, and/or cytokine production in assays to quantitate the immunostimulatory response of particular siNA molecules (see, for example, Leifer et al., 2003, J. Immunother. 26, 313-9; and U.S. Pat. No. 5,968,909, incorporated in its entirety by reference).

In one embodiment, the invention features siNA constructs that mediate RNAi against SCD, wherein the siNA construct comprises one or more chemical modifications described herein that modulates the binding affinity between the sense and antisense strands of the siNA construct.

In another embodiment, the invention features a method for generating siNA molecules with increased binding affinity between the sense and antisense strands of the siNA molecule comprising (a) introducing nucleotides having any of Formula I-VII or any combination thereof into an siNA molecule, and (b) assaying the siNA molecule of step (a) under conditions suitable for isolating siNA molecules having increased binding affinity between the sense and antisense strands of the siNA molecule.

In one embodiment, the invention features siNA constructs that mediate RNAi against SCD, wherein the siNA construct comprises one or more chemical modifications described herein that modulates the binding affinity between the antisense strand of the siNA construct and a complementary target RNA sequence within a cell.

In one embodiment, the invention features siNA constructs that mediate RNAi against SCD, wherein the siNA construct comprises one or more chemical modifications described herein that modulates the binding affinity between the antisense strand of the siNA construct and a complementary target DNA sequence within a cell.

In another embodiment, the invention features a method for generating siNA molecules with increased binding affinity between the antisense strand of the siNA molecule and a complementary target RNA sequence comprising (a) introducing nucleotides having any of Formula I-VII or any combination thereof into an siNA molecule, and (b) assaying the siNA molecule of step (a) under conditions suitable for isolating siNA molecules having increased binding affinity between the antisense strand of the siNA molecule and a complementary target RNA sequence.

In another embodiment, the invention features a method for generating siNA molecules with increased binding affinity between the antisense strand of the siNA molecule and a complementary target DNA sequence comprising (a) introducing nucleotides having any of Formula I-VII or any combination thereof into an siNA molecule, and (b) assaying the siNA molecule of step (a) under conditions suitable for isolating siNA molecules having increased binding affinity between the antisense strand of the siNA molecule and a complementary target DNA sequence.

In one embodiment, the invention features siNA constructs that mediate RNAi against SCD, wherein the siNA construct comprises one or more chemical modifications described herein that modulate the polymerase activity of a cellular polymerase capable of generating additional endogenous siNA molecules having sequence homology to the chemically modified siNA construct.

In another embodiment, the invention features a method for generating siNA molecules capable of mediating increased polymerase activity of a cellular polymerase capable of generating additional endogenous siNA molecules having sequence homology to a chemically modified siNA molecule comprising (a) introducing nucleotides having any of Formula I-VII or any combination thereof into an siNA molecule, and (b) assaying the siNA molecule of step (a) under conditions suitable for isolating siNA molecules capable of mediating increased polymerase activity of a cellular polymerase capable of generating additional endogenous siNA molecules having sequence homology to the chemically modified siNA molecule.

In one embodiment, the invention features chemically modified siNA constructs that mediate RNAi against SCD in a cell, wherein the chemical modifications do not significantly effect the interaction of siNA with a target RNA molecule, DNA molecule and/or proteins or other factors that are essential for RNAi in a manner that would decrease the efficacy of RNAi mediated by such siNA constructs.

In another embodiment, the invention features a method for generating siNA molecules with improved RNAi activity against SCD comprising (a) introducing nucleotides having any of Formula I-VII or any combination thereof into an siNA molecule, and (b) assaying the siNA molecule of step (a) under conditions suitable for isolating siNA molecules having improved RNAi activity.

In yet another embodiment, the invention features a method for generating siNA molecules with improved RNAi activity against SCD target RNA comprising (a) introducing nucleotides having any of Formula I-VII or any combination thereof into an siNA molecule, and (b) assaying the siNA molecule of step (a) under conditions suitable for isolating siNA molecules having improved RNAi activity against the target RNA.

In yet another embodiment, the invention features a method for generating siNA molecules with improved RNAi activity against SCD target DNA comprising (a) introducing nucleotides having any of Formula I-VII or any combination thereof into an siNA molecule, and (b) assaying the siNA molecule of step (a) under conditions suitable for isolating siNA molecules having improved RNAi activity against the target DNA.

In one embodiment, the invention features siNA constructs that mediate RNAi against SCD, wherein the siNA construct comprises one or more chemical modifications described herein that modulates the cellular uptake of the siNA construct.

In another embodiment, the invention features a method for generating siNA molecules against SCD with improved cellular uptake comprising (a) introducing nucleotides having any of Formula I-VII or any combination thereof into an siNA molecule, and (b) assaying the siNA molecule of step (a) under conditions suitable for isolating siNA molecules having improved cellular uptake.

In one embodiment, the invention features siNA constructs that mediate RNAi against SCD, wherein the siNA construct comprises one or more chemical modifications described herein that increases the bioavailability of the siNA construct, for example, by attaching polymeric conjugates such as polyethyleneglycol or equivalent conjugates that improve the pharmacokinetics of the siNA construct, or by attaching conjugates that target specific tissue types or cell types in vivo. Non-limiting examples of such conjugates are described in Vargeese et al., U.S. Ser. No. 10/201,394 incorporated by reference herein.

In one embodiment, the invention features a method for generating siNA molecules of the invention with improved bioavailability comprising (a) introducing a conjugate into the structure of an siNA molecule, and (b) assaying the siNA molecule of step (a) under conditions suitable for isolating siNA molecules having improved bioavailability. Such conjugates can include ligands for cellular receptors, such as peptides derived from naturally occurring protein ligands; protein localization sequences, including cellular ZIP code sequences; antibodies; nucleic acid aptamers; vitamins and other co-factors, such as folate and N-acetylgalactosamine; polymers, such as polyethyleneglycol (PEG); phospholipids; cholesterol; polyamines, such as spermine or spermidine; and others.

In one embodiment, the invention features a double-stranded short interfering nucleic acid (siNA) molecule that comprises a first nucleotide sequence complementary to a target RNA sequence or a portion thereof, and a second sequence having complementarity to said first sequence, wherein said second sequence is chemically modified in a manner that it can no longer act as a guide sequence for efficiently mediating RNA interference and/or be recognized by cellular proteins that facilitate RNAi.

In one embodiment, the invention features a double-stranded short interfering nucleic acid (siNA) molecule that comprises a first nucleotide sequence complementary to a target RNA sequence or a portion thereof, and a second sequence having complementarity to said first sequence, wherein the second sequence is designed or modified in a manner that prevents its entry into the RNAi pathway as a guide sequence or as a sequence that is complementary to a target nucleic acid (e.g., RNA) sequence. Such design or modifications are expected to enhance the activity of siNA and/or improve the specificity of siNA molecules of the invention. These modifications are also expected to minimize any off-target effects and/or associated toxicity.

In one embodiment, the invention features a double-stranded short interfering nucleic acid (siNA) molecule that comprises a first nucleotide sequence complementary to a target RNA sequence or a portion thereof, and a second sequence having complementarity to said first sequence, wherein said second sequence is incapable of acting as a guide sequence for mediating RNA interference.

In one embodiment, the invention features a double-stranded short interfering nucleic acid (siNA) molecule that comprises a first nucleotide sequence complementary to a target RNA sequence or a portion thereof, and a second sequence having complementarity to said first sequence, wherein said second sequence does not have a terminal 5′-hydroxyl (5′-OH) or 5′-phosphate group.

In one embodiment, the invention features a double-stranded short interfering nucleic acid (siNA) molecule that comprises a first nucleotide sequence complementary to a target RNA sequence or a portion thereof, and a second sequence having complementarity to said first sequence, wherein said second sequence comprises a terminal cap moiety at the 5′-end of said second sequence. In one embodiment, the terminal cap moiety comprises an inverted abasic, inverted deoxy abasic, inverted nucleotide moiety, a group shown in FIG. 10, an alkyl or cycloalkyl group, a heterocycle, or any other group that prevents RNAi activity in which the second sequence serves as a guide sequence or template for RNAi.

In one embodiment, the invention features a double-stranded short interfering nucleic acid (siNA) molecule that comprises a first nucleotide sequence complementary to a target RNA sequence or a portion thereof, and a second sequence having complementarity to said first sequence, wherein said second sequence comprises a terminal cap moiety at the 5′-end and 3′-end of said second sequence. In one embodiment, each terminal cap moiety individually comprises an inverted abasic, inverted deoxy abasic, inverted nucleotide moiety, a group shown in FIG. 10, an alkyl or cycloalkyl group, a heterocycle, or any other group that prevents RNAi activity in which the second sequence serves as a guide sequence or template for RNAi.

In one embodiment, the invention features a method for generating siNA molecules of the invention with improved specificity for down regulating or inhibiting the expression of a target nucleic acid (e.g., a DNA or RNA such as a gene or its corresponding RNA), comprising (a) introducing one or more chemical modifications into the structure of an siNA molecule, and (b) assaying the siNA molecule of step (a) under conditions suitable for isolating siNA molecules having improved specificity. In another embodiment, the chemical modification used to improve specificity comprises terminal cap modifications at the 5′-end, 3′-end, or both 5′ and 3′-ends of the siNA molecule. The terminal cap modifications can comprise, for example, structures shown in FIG. 10 (e.g. inverted deoxyabasic moieties) or any other chemical modification that renders a portion of the siNA molecule (e.g. the sense strand) incapable of mediating RNA interference against an off target nucleic acid sequence. In a non-limiting example, an siNA molecule is designed such that only the antisense sequence of the siNA molecule can serve as a guide sequence for RISC mediated degradation of a corresponding target RNA sequence. This can be accomplished by rendering the sense sequence of the siNA inactive by introducing chemical modifications to the sense strand that preclude recognition of the sense strand as a guide sequence by RNAi machinery. In one embodiment, such chemical modifications comprise any chemical group at the 5′-end of the sense strand of the siNA, or any other group that serves to render the sense strand inactive as a guide sequence for mediating RNA interference. These modifications, for example, can result in a molecule where the 5′-end of the sense strand no longer has a free 5′-hydroxyl (5′-OH) or a free 5′-phosphate group (e.g., phosphate, diphosphate, triphosphate, cyclic phosphate etc.). Non-limiting examples of such siNA constructs are described herein, such as “Stab 9/1”, “Stab 7/8”, “Stab 7/19”, “Stab 17/22”, “Stab 23/24”, “Stab 24/25”, and “Stab 24/26” (e.g., any siNA having Stab 7, 9, 17, 23, or 24 sense strands) chemistries and variants thereof (see Table IV) wherein the 5′-end and 3′-end of the sense strand of the siNA do not comprise a hydroxyl group or phosphate group.

In one embodiment, the invention features a method for generating siNA molecules of the invention with improved specificity for down regulating or inhibiting the expression of a target nucleic acid (e.g., a DNA or RNA such as a gene or its corresponding RNA), comprising introducing one or more chemical modifications into the structure of an siNA molecule that prevent a strand or portion of the siNA molecule from acting as a template or guide sequence for RNAi activity. In one embodiment, the inactive strand or sense region of the siNA molecule is the sense strand or sense region of the siNA molecule, i.e. the strand or region of the siNA that does not have complementarity to the target nucleic acid sequence. In one embodiment, such chemical modifications comprise any chemical group at the 5′-end of the sense strand or region of the siNA that does not comprise a 5′-hydroxyl (5′-OH) or 5′-phosphate group, or any other group that serves to render the sense strand or sense region inactive as a guide sequence for mediating RNA interference. Non-limiting examples of such siNA constructs are described herein, such as “Stab 9/10”, “Stab 7/8”, “Stab 7/19”, “Stab 17/22”, “Stab 23/24”, “Stab 24/25”, and “Stab 24/26” (e.g., any siNA having Stab 7, 9, 17, 23, or 24 sense strands) chemistries and variants thereof (see Table IV) wherein the 5′-end and 3′-end of the sense strand of the siNA do not comprise a hydroxyl group or phosphate group.

In one embodiment, the invention features a method for screening siNA molecules that are active in mediating RNA interference against a target nucleic acid sequence comprising (a) generating a plurality of unmodified siNA molecules, (b) screening the siNA molecules of step (a) under conditions suitable for isolating siNA molecules that are active in mediating RNA interference against the target nucleic acid sequence, and (c) introducing chemical modifications (e.g. chemical modifications as described herein or as otherwise known in the art) into the active siNA molecules of (b). In one embodiment, the method further comprises re-screening the chemically modified siNA molecules of step (c) under conditions suitable for isolating chemically modified siNA molecules that are active in mediating RNA interference against the target nucleic acid sequence.

In one embodiment, the invention features a method for screening chemically modified siNA molecules that are active in mediating RNA interference against a target nucleic acid sequence comprising (a) generating a plurality of chemically modified siNA molecules (e.g. siNA molecules as described herein or as otherwise known in the art), and (b) screening the siNA molecules of step (a) under conditions suitable for isolating chemically modified siNA molecules that are active in mediating RNA interference against the target nucleic acid sequence.

The term “ligand” refers to any compound or molecule, such as a drug, peptide, hormone, or neurotransmitter that is capable of interacting with another compound, such as a receptor, either directly or indirectly. The receptor that interacts with a ligand can be present on the surface of a cell or can alternately be an intercellular receptor. Interaction of the ligand with the receptor can result in a biochemical reaction, or can simply be a physical interaction or association.

In another embodiment, the invention features a method for generating siNA molecules of the invention with improved bioavailability comprising (a) introducing an excipient formulation to an siNA molecule, and (b) assaying the siNA molecule of step (a) under conditions suitable for isolating siNA molecules having improved bioavailability. Such excipients include polymers such as cyclodextrins, lipids, cationic lipids, polyamines, phospholipids, nanoparticles, receptors, ligands, and others.

In another embodiment, the invention features a method for generating siNA molecules of the invention with improved bioavailability comprising (a) introducing nucleotides having any of Formulae I-VII or any combination thereof into an siNA molecule, and (b) assaying the siNA molecule of step (a) under conditions suitable for isolating siNA molecules having improved bioavailability.

In another embodiment, polyethylene glycol (PEG) can be covalently attached to siNA compounds of the present invention. The attached PEG can be any molecular weight, preferably from about 2,000 to about 50,000 daltons (Da).

The present invention can be used alone or as a component of a kit having at least one of the reagents necessary to carry out the in vitro or in vivo introduction of RNA to test samples and/or subjects. For example, preferred components of the kit include an siNA molecule of the invention and a vehicle that promotes introduction of the siNA into cells of interest as described herein (e.g., using lipids and other methods of transfection known in the art, see for example Beigelman et al, U.S. Pat. No. 6,395,713). The kit can be used for target validation, such as in determining gene function and/or activity, or in drug optimization, and in drug discovery (see for example Usman et al., U.S. Ser. No. 60/402,996). Such a kit can also include instructions to allow a user of the kit to practice the invention.

The term “short interfering nucleic acid”, “siNA”, “short interfering RNA”, “siRNA”, “short interfering nucleic acid molecule”, “short interfering oligonucleotide molecule”, or “chemically modified short interfering nucleic acid molecule” as used herein refers to any nucleic acid molecule capable of inhibiting or down regulating gene expression or viral replication, for example by mediating RNA interference “RNAi” or gene silencing in a sequence-specific manner; see for example Zamore et al., 2000, Cell, 101, 25-33; Bass, 2001, Nature, 411, 428-429; Elbashir et al., 2001, Nature, 411, 494-498; and Kreutzer et al., International PCT Publication No. WO 00/44895; Zernicka-Goetz et al., International PCT Publication No. WO 01/36646; Fire, International PCT Publication No. WO 99/32619; Plaetinck et al., International PCT Publication No. WO 00/01846; Mello and Fire, International PCT Publication No. WO 01/29058; Deschamps-Depaillette, International PCT Publication No. WO 99/07409; and Li et al., International PCT Publication No. WO 00/44914; Allshire, 2002, Science, 297, 1818-1819; Volpe et al., 2002, Science, 297, 1833-1837; Jenuwein, 2002, Science, 297, 2215-2218; and Hall et al., 2002, Science, 297, 2232-2237; Hutvagner and Zamore, 2002, Science, 297, 2056-60; McManus et al., 2002, RNA, 8, 842-850; Reinhart et al., 2002, Gene & Dev., 16, 1616-1626; and Reinhart & Bartel, 2002, Science, 297, 1831). Non limiting examples of siNA molecules of the invention are shown in FIGS. 4-6, and Tables II and III herein. For example the siNA can be a double-stranded polynucleotide molecule comprising self-complementary sense and antisense regions, wherein the antisense region comprises nucleotide sequence that is complementary to nucleotide sequence in a target nucleic acid molecule or a portion thereof and the sense region having nucleotide sequence corresponding to the target nucleic acid sequence or a portion thereof. The siNA can be assembled from two separate oligonucleotides, where one strand is the sense strand and the other is the antisense strand, wherein the antisense and sense strands are self-complementary (i.e. each strand comprises nucleotide sequence that is complementary to nucleotide sequence in the other strand; such as where the antisense strand and sense strand form a duplex or double-stranded structure, for example wherein the double-stranded region is about 15 to about 30, e.g., about 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29 or 30 base pairs; the antisense strand comprises nucleotide sequence that is complementary to nucleotide sequence in a target nucleic acid molecule or a portion thereof and the sense strand comprises nucleotide sequence corresponding to the target nucleic acid sequence or a portion thereof (e.g., about 15 to about 25 or more nucleotides of the siNA molecule are complementary to the target nucleic acid or a portion thereof). Alternatively, the siNA is assembled from a single oligonucleotide, where the self-complementary sense and antisense regions of the siNA are linked by means of a nucleic acid based or non-nucleic acid-based linker(s). The siNA can be a polynucleotide with a duplex, asymmetric duplex, hairpin or asymmetric hairpin secondary structure, having self-complementary sense and antisense regions, wherein the antisense region comprises nucleotide sequence that is complementary to nucleotide sequence in a separate target nucleic acid molecule or a portion thereof and the sense region having nucleotide sequence corresponding to the target nucleic acid sequence or a portion thereof. The siNA can be a circular single-stranded polynucleotide having two or more loop structures and a stem comprising self-complementary sense and antisense regions, wherein the antisense region comprises nucleotide sequence that is complementary to nucleotide sequence in a target nucleic acid molecule or a portion thereof and the sense region having nucleotide sequence corresponding to the target nucleic acid sequence or a portion thereof, and wherein the circular polynucleotide can be processed either in vivo or in vitro to generate an active siNA molecule capable of mediating RNAi. The siNA can also comprise a single-stranded polynucleotide having nucleotide sequence complementary to nucleotide sequence in a target nucleic acid molecule or a portion thereof (for example, where such siNA molecule does not require the presence within the siNA molecule of nucleotide sequence corresponding to the target nucleic acid sequence or a portion thereof), wherein the single-stranded polynucleotide can further comprise a terminal phosphate group, such as a 5′-phosphate (see for example Martinez et al., 2002, Cell., 110, 563-574 and Schwarz et al., 2002, Molecular Cell, 10, 537-568), or 5′,3′-diphosphate. In certain embodiments, the siNA molecule of the invention comprises separate sense and antisense sequences or regions, wherein the sense and antisense regions are covalently linked by nucleotide or non-nucleotide linkers molecules as is known in the art, or are alternately non-covalently linked by ionic interactions, hydrogen bonding, van der waals interactions, hydrophobic interactions, and/or stacking interactions. In certain embodiments, the siNA molecules of the invention comprise nucleotide sequence that is complementary to nucleotide sequence of a target gene. In another embodiment, the siNA molecule of the invention interacts with nucleotide sequence of a target gene in a manner that causes inhibition of expression of the target gene. As used herein, siNA molecules need not be limited to those molecules containing only RNA, but further encompasses chemically modified nucleotides and non-nucleotides. In certain embodiments, the short interfering nucleic acid molecules of the invention lack 2′-hydroxy (2′-OH) containing nucleotides. Applicant describes in certain embodiments short interfering nucleic acids that do not require the presence of nucleotides having a 2′-hydroxy group for mediating RNAi and as such, short interfering nucleic acid molecules of the invention optionally do not include any ribonucleotides (e.g., nucleotides having a 2′-OH group). Such siNA molecules that do not require the presence of ribonucleotides within the siNA molecule to support RNAi can however have an attached linker or linkers or other attached or associated groups, moieties, or chains containing one or more nucleotides with 2′-OH groups. Optionally, siNA molecules can comprise ribonucleotides at about 5, 10, 20, 30, 40, or 50% of the nucleotide positions. The modified short interfering nucleic acid molecules of the invention can also be referred to as short interfering modified oligonucleotides “siMON.” As used herein, the term siNA is meant to be equivalent to other terms used to describe nucleic acid molecules that are capable of mediating sequence specific RNAi, for example short interfering RNA (siRNA), double-stranded RNA (dsRNA), micro-RNA (miRNA), short hairpin RNA (shRNA), short interfering oligonucleotide, short interfering nucleic acid, short interfering modified oligonucleotide, chemically modified siRNA, post-transcriptional gene silencing RNA (ptgsRNA), and others. In addition, as used herein, the term RNAi is meant to be equivalent to other terms used to describe sequence specific RNA interference, such as post transcriptional gene silencing, translational inhibition, or epigenetics. For example, siNA molecules of the invention can be used to epigenetically silence genes at both the post-transcriptional level and the pre-transcriptional level. In a non-limiting example, epigenetic regulation of gene expression by siNA molecules of the invention can result from siNA mediated modification of chromatin structure or methylation pattern to alter gene expression (see, for example, Verdel et al., 2004, Science, 303, 672-676; Pal-Bhadra et al., 2004, Science, 303, 669-672; Allshire, 2002, Science, 297, 1818-1819; Volpe et al., 2002, Science, 297, 1833-1837; Jenuwein, 2002, Science, 297, 2215-2218; and Hall et al., 2002, Science, 297, 2232-2237).

In one embodiment, an siNA molecule of the invention is a duplex forming oligonucleotide “DFO”, (see for example FIGS. 14-15 and Vaish et al., U.S. Ser. No. 10/727,780 filed Dec. 3, 2003 and International PCT Application No. US04/16390, filed May 24, 2004).

In one embodiment, an siNA molecule of the invention is a multifunctional siNA, (see for example FIGS. 16-21 and Jadhav et al., U.S. Ser. No. 60/543,480 filed Feb. 10, 2004 and International PCT Application No. US04/16390, filed May 24, 2004). The multifunctional siNA of the invention can comprise sequence targeting, for example, two regions of SCD RNA (see for example target sequences in Tables II and III).

By “asymmetric hairpin” as used herein is meant a linear siNA molecule comprising an antisense region, a loop portion that can comprise nucleotides or non-nucleotides, and a sense region that comprises fewer nucleotides than the antisense region to the extent that the sense region has enough complementary nucleotides to base pair with the antisense region and form a duplex with loop. For example, an asymmetric hairpin siNA molecule of the invention can comprise an antisense region having length sufficient to mediate RNAi in a cell or in vitro system (e.g. about 15 to about 30, or about 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, or 30 nucleotides) and a loop region comprising about 4 to about 12 (e.g., about 4, 5, 6, 7, 8, 9, 10, 11, or 12) nucleotides, and a sense region having about 3 to about 25 (e.g., about 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, or 25) nucleotides that are complementary to the antisense region. The asymmetric hairpin siNA molecule can also comprise a 5′-terminal phosphate group that can be chemically modified. The loop portion of the asymmetric hairpin siNA molecule can comprise nucleotides, non-nucleotides, linker molecules, or conjugate molecules as described herein.

By “asymmetric duplex” as used herein is meant an siNA molecule having two separate strands comprising a sense region and an antisense region, wherein the sense region comprises fewer nucleotides than the antisense region to the extent that the sense region has enough complementary nucleotides to base pair with the antisense region and form a duplex. For example, an asymmetric duplex siNA molecule of the invention can comprise an antisense region having length sufficient to mediate RNAi in a cell or in vitro system (e.g. about 15 to about 30, or about 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, or 30 nucleotides) and a sense region having about 3 to about 25 (e.g., about 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, or 25) nucleotides that are complementary to the antisense region.

By “modulate” is meant that the expression of the gene, or level of RNA molecule or equivalent RNA molecules encoding one or more proteins or protein subunits, or activity of one or more proteins or protein subunits is up regulated or down regulated, such that expression, level, or activity is greater than or less than that observed in the absence of the modulator. For example, the term “modulate” can mean “inhibit,” but the use of the word “modulate” is not limited to this definition.

By “inhibit”, “down-regulate”, or “reduce”, it is meant that the expression of the gene, or level of RNA molecules or equivalent RNA molecules encoding one or more proteins or protein subunits, or activity of one or more proteins or protein subunits, is reduced below that observed in the absence of the nucleic acid molecules (e.g., siNA) of the invention. In one embodiment, inhibition, down-regulation or reduction with an siNA molecule is below that level observed in the presence of an inactive or attenuated molecule. In another embodiment, inhibition, down-regulation, or reduction with siNA molecules is below that level observed in the presence of, for example, an siNA molecule with scrambled sequence or with mismatches. In another embodiment, inhibition, down-regulation, or reduction of gene expression with a nucleic acid molecule of the instant invention is greater in the presence of the nucleic acid molecule than in its absence. In one embodiment, inhibition, down regulation, or reduction of gene expression is associated with post transcriptional silencing, such as RNAi mediated cleavage of a target nucleic acid molecule (e.g. RNA) or inhibition of translation. In one embodiment, inhibition, down regulation, or reduction of gene expression is associated with pretranscriptional silencing.

By “gene”, or “target gene”, is meant a nucleic acid that encodes an RNA, for example, nucleic acid sequences including, but not limited to, structural genes encoding a polypeptide. A gene or target gene can also encode a functional RNA (FRNA) or non-coding RNA (ncRNA), such as small temporal RNA (stRNA), micro RNA (miRNA), small nuclear RNA (snRNA), short interfering RNA (siRNA), small nucleolar RNA (snRNA), ribosomal RNA (rRNA), transfer RNA (tRNA) and precursor RNAs thereof. Such non-coding RNAs can serve as target nucleic acid molecules for siNA mediated RNA interference in modulating the activity of fRNA or ncRNA involved in functional or regulatory cellular processes. Aberrant FRNA or ncRNA activity leading to disease can therefore be modulated by siNA molecules of the invention. siNA molecules targeting FRNA and ncRNA can also be used to manipulate or alter the genotype or phenotype of a subject, organism or cell, by intervening in cellular processes such as genetic imprinting, transcription, translation, or nucleic acid processing (e.g., transamination, methylation etc.). The target gene can be a gene derived from a cell, an endogenous gene, a transgene, or exogenous genes such as genes of a pathogen, for example a virus, which is present in the cell after infection thereof. The cell containing the target gene can be derived from or contained in any organism, for example a plant, animal, protozoan, virus, bacterium, or fungus. Non-limiting examples of plants include monocots, dicots, or gymnosperms. Non-limiting examples of animals include vertebrates or invertebrates. Non-limiting examples of fungi include molds or yeasts. For a review, see for example Snyder and Gerstein, 2003, Science, 300, 258-260.

By “non-canonical base pair” is meant any non-Watson Crick base pair, such as mismatches and/or wobble base pairs, including flipped mismatches, single hydrogen bond mismatches, trans-type mismatches, triple base interactions, and quadruple base interactions. Non-limiting examples of such non-canonical base pairs include, but are not limited to, AC reverse Hoogsteen, AC wobble, AU reverse Hoogsteen, GU wobble, AA N7 amino, CC 2-carbonyl-amino(H1)-N-3-amino(H2), GA sheared, UC 4-carbonyl-amino, UU imino-carbonyl, AC reverse wobble, AU Hoogsteen, AU reverse Watson Crick, CG reverse Watson Crick, GC N3-amino-amino N3, AA N1-amino symmetric, AA N7-amino symmetric, GA N7-N1 amino-carbonyl, GA+ carbonyl-amino N7-N1, GG N1-carbonyl symmetric, GG N3-amino symmetric, CC carbonyl-amino symmetric, CC N3-amino symmetric, UU 2-carbonyl-imino symmetric, UU 4-carbonyl-imino symmetric, AA amino-N3, AA N1-amino, AC amino 2-carbonyl, AC N3-amino, AC N7-amino, AU amino-4-carbonyl, AU NI-imino, AU N3-imino, AU N7-imino, CC carbonyl-amino, GA amino-N1, GA amino-N7, GA carbonyl-amino, GA N3-amino, GC amino-N3, GC carbonyl-amino, GC N3-amino, GC N7-amino, GG amino-N7, GG carbonyl-imino, GG N7-amino, GU amino-2-carbonyl, GU carbonyl-imino, GU imino-2-carbonyl, GU N7-imino, psiU imino-2-carbonyl, UC 4-carbonyl-amino, UC imino-carbonyl, UU imino4-carbonyl, AC C2-H-N3, GA carbonyl-C2-H, UU imino-4-carbonyl 2 carbonyl-C5-H, AC amino(A) N3(C)-carbonyl, GC imino amino-carbonyl, Gpsi imino-2-carbonyl amino-2-carbonyl, and GU imino amino-2-carbonyl base pairs.

By “SCD” as used herein is meant, any stearoyl-CoA desaturase protein, peptide, or polypeptide having any stearoyl-CoA desaturase activity, such as encoded by SCD Genbank Accession Nos. shown in Table I. The term SCD also refers to nucleic acid sequences encoding any stearoyl-CoA desaturase protein, peptide, or polypeptide having SCD activity. The term “SCD” is also meant to include other SCD encoding sequence, such as other SCD isoforms, mutant SCD genes, splice variants of SCD genes, and SCD gene polymorphisms.

By “homologous sequence” is meant, a nucleotide sequence that is shared by one or more polynucleotide sequences, such as genes, gene transcripts and/or non-coding polynucleotides. For example, a homologous sequence can be a nucleotide sequence that is shared by two or more genes encoding related but different proteins, such as different members of a gene family, different protein epitopes, different protein isoforms or completely divergent genes, such as a cytokine and its corresponding receptors. A homologous sequence can be a nucleotide sequence that is shared by two or more non-coding polynucleotides, such as noncoding DNA or RNA, regulatory sequences, introns, and sites of transcriptional control or regulation. Homologous sequences can also include conserved sequence regions shared by more than one polynucleotide sequence. Homology does not need to be perfect homology (e.g., 100%), as partially homologous sequences are also contemplated by the instant invention (e.g., 99%, 98%, 97%, 96%, 95%, 94%, 93%, 92%, 91%, 90%, 89%, 88%, 87%, 86%, 85%, 84%, 83%, 82%, 81%, 80% etc.).

By “conserved sequence region” is meant, a nucleotide sequence of one or more regions in a polynucleotide does not vary significantly between generations or from one biological system, subject, or organism to another biological system, subject, or organism. The polynucleotide can include both coding and non-coding DNA and RNA.

By “sense region” is meant a nucleotide sequence of an siNA molecule having complementarity to an antisense region of the siNA molecule. In addition, the sense region of an siNA molecule can comprise a nucleic acid sequence having homology with a target nucleic acid sequence.

By “antisense region” is meant a nucleotide sequence of an siNA molecule having complementarity to a target nucleic acid sequence. In addition, the antisense region of an siNA molecule can optionally comprise a nucleic acid sequence having complementarity to a sense region of the siNA molecule.

By “target nucleic acid” is meant any nucleic acid sequence whose expression or activity is to be modulated. The target nucleic acid can be DNA or RNA.

By “complementarity” is meant that a nucleic acid can form hydrogen bond(s) with another nucleic acid sequence by either traditional Watson-Crick or other non-traditional types. In reference to the nucleic molecules of the present invention, the binding free energy for a nucleic acid molecule with its complementary sequence is sufficient to allow the relevant function of the nucleic acid to proceed, e.g., RNAi activity. Determination of binding free energies for nucleic acid molecules is well known in the art (see, e.g., Turner et al., 1987, CSH Symp. Quant. Biol. LII pp. 123-133; Frier et al., 1986, Proc. Nat. Acad. Sci. USA 83:9373-9377; Turner et al., 1987, J. Am. Chem. Soc. 109:3783-3785). A percent complementarity indicates the percentage of contiguous residues in a nucleic acid molecule that can form hydrogen bonds (e.g., Watson-Crick base pairing) with a second nucleic acid sequence (e.g., 5, 6, 7, 8, 9, or 10 nucleotides out of a total of 10 nucleotides in the first oligonucleotide being based paired to a second nucleic acid sequence having 10 nucleotides represents 50%, 60%, 70%, 80%, 90%, and 100% complementary respectively). “Perfectly complementary” means that all the contiguous residues of a nucleic acid sequence will hydrogen bond with the same number of contiguous residues in a second nucleic acid sequence. In one embodiment, an siNA molecule of the invention comprises about 15 to about 30 or more (e.g.; about 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, or 30 or more) nucleotides that are complementary to one or more target nucleic acid molecules or a portion thereof.

In one embodiment, siNA molecules of the invention that down regulate or reduce SCD gene expression are used for preventing or treating diabetes (type I and/or type II), atherosclerosis, cancer, obesity, and viral infection in a subject or organism.

In one embodiment, the siNA molecules of the invention, are used to treat diabetes (type I and/or type II), atherosclerosis, cancer, obesity, and viral infection in a subject or organism.

In one embodiment, the siNA molecules of the invention are used to induce or promote weight loss in a subject or organism. In one embodiment, the siNA molecules of the invention are used to lower the amount of body fat in a subject or organism.

By “cancer” as used herein is meant, any disease, condition, trait, genotype or phenotype characterized by unregulated cell growth or replication as is known in the art; including AIDS related cancers such as Kaposi's sarcoma; breast cancers; bone cancers such as Osteosarcoma, Chondrosarcomas, Ewing's sarcoma, Fibrosarcomas, Giant cell tumors, Adamantinomas, and Chordomas; Brain cancers such as Meningiomas, Glioblastomas, Lower-Grade Astrocytomas, Oligodendrocytomas, Pituitary Tumors, Schwannomas, and Metastatic brain cancers; cancers of the head and neck including various lymphomas such as mantle cell lymphoma, non-Hodgkins lymphoma, adenoma, squamous cell carcinoma, laryngeal carcinoma, gallbladder and bile duct cancers, cancers of the retina such as retinoblastoma, cancers of the esophagus, gastric cancers, multiple myeloma, ovarian cancer, uterine cancer, thyroid cancer, testicular cancer, endometrial cancer, melanoma, colorectal cancer, lung cancer, bladder cancer, prostate cancer, lung cancer (including non-small cell lung carcinoma), pancreatic cancer, sarcomas, Wilms' tumor, cervical cancer, head and neck cancer, skin cancers, nasopharyngeal carcinoma, liposarcoma, epithelial carcinoma, renal cell carcinoma, gallbladder adeno carcinoma, parotid adenocarcinoma, endometrial sarcoma, multidrug resistant cancers; and any other cancer that can respond to the modulation of disease related gene expression in a cell or tissue, alone or in combination with other therapies.

In one embodiment of the present invention, each sequence of an siNA molecule of the invention is independently about 15 to about 30 nucleotides in length, in specific embodiments about 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, or 30 nucleotides in length. In another embodiment, the siNA duplexes of the invention independently comprise about 15 to about 30 base pairs (e.g., about 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, or 30). In another embodiment, one or more strands of the siNA molecule of the invention independently comprises about 15 to about 30 nucleotides (e.g., about 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, or 30) that are complementary to a target nucleic acid molecule. In yet another embodiment, siNA molecules of the invention comprising hairpin or circular structures are about 35 to about 55 (e.g., about 35, 40, 45, 50 or 55) nucleotides in length, or about 38 to about 44 (e.g., about 38, 39, 40, 41, 42, 43, or 44) nucleotides in length and comprising about 15 to about 25 (e.g., about 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, or 25) base pairs. Exemplary siNA molecules of the invention are shown in Table II. Exemplary synthetic siNA molecules of the invention are shown in Table III and/or FIGS. 4-5.

As used herein “cell” is used in its usual biological sense, and does not refer to an entire multicellular organism, e.g., specifically does not refer to a human. The cell can be present in an organism, e.g., birds, plants and mammals such as humans, cows, sheep, apes, monkeys, swine, dogs, and cats. The cell can be prokaryotic (e.g., bacterial cell) or eukaryotic (e.g., mammalian or plant cell). The cell can be of somatic or germ line origin, totipotent or pluripotent, dividing or non-dividing. The cell can also be derived from or can comprise a gamete or embryo, a stem cell, or a fully differentiated cell.

The siNA molecules of the invention are added directly, or can be complexed with cationic lipids, packaged within liposomes, or otherwise delivered to target cells or tissues. The nucleic acid or nucleic acid complexes can be locally administered to relevant tissues ex vivo, or in vivo through direct dermal application, transdermal application, or injection, with or without their incorporation in biopolymers. In particular embodiments, the nucleic acid molecules of the invention comprise sequences shown in Tables II-III and/or FIGS. 4-5. Examples of such nucleic acid molecules consist essentially of sequences defined in these tables and figures. Furthermore, the chemically modified constructs described in Table IV can be applied to any siNA sequence of the invention.

In another aspect, the invention provides mammalian cells containing one or more siNA molecules of this invention. The one or more siNA molecules can independently be targeted to the same or different sites.

By “RNA” is meant a molecule comprising at least one ribonucleotide residue. By “ribonucleotide” is meant a nucleotide with a hydroxyl group at the 2′ position of a β-D-ribofuranose moiety. The terms include double-stranded RNA, single-stranded RNA, isolated RNA such as partially purified RNA, essentially pure RNA, synthetic RNA, recombinantly produced RNA, as well as altered RNA that differs from naturally occurring RNA by the addition, deletion, substitution and/or alteration of one or more nucleotides. Such alterations can include addition of non-nucleotide material, such as to the end(s) of the siNA or internally, for example at one or more nucleotides of the RNA. Nucleotides in the RNA molecules of the instant invention can also comprise non-standard nucleotides, such as non-naturally occurring nucleotides or chemically synthesized nucleotides or deoxynucleotides. These altered RNAs can be referred to as analogs or analogs of naturally-occurring RNA.

By “subject” is meant an organism, which is a donor or recipient of explanted cells or the cells themselves. “Subject” also refers to an organism to which the nucleic acid molecules of the invention can be administered. A subject can be a mammal or mammalian cells, including a human or human cells.

The term “phosphorothioate” as used herein refers to an internucleotide linkage having Formula I, wherein Z and/or W comprise a sulfur atom. Hence, the term phosphorothioate refers to both phosphorothioate and phosphorodithioate internucleotide linkages.

The term “phosphonoacetate” as used herein refers to an internucleotide linkage having Formula I, wherein Z and/or W comprise an acetyl or protected acetyl group.

The term “thiophosphonoacetate” as used herein refers to an internucleotide linkage having Formula I, wherein Z comprises an acetyl or protected acetyl group and W comprises a sulfur atom or alternately W comprises an acetyl or protected acetyl group and Z comprises a sulfur atom.

The term “universal base” as used herein refers to nucleotide base analogs that form base pairs with each of the natural DNA/RNA bases with little discrimination between them. Non-limiting examples of universal bases include C-phenyl, C-naphthyl and other aromatic derivatives, inosine, azole carboxamides, and nitroazole derivatives such as 3-nitropyrrole, 4-nitroindole, 5-nitroindole, and 6-nitroindole as known in the art (see for example Loakes, 2001, Nucleic Acids Research, 29, 2437-2447).

The term “acyclic nucleotide” as used herein refers to any nucleotide having an acyclic ribose sugar.

The nucleic acid molecules of the instant invention, individually, or in combination or in conjunction with other drugs, can be used to for preventing or treating diabetes (type I and/or type II), atherosclerosis, cancer, obesity, and viral infection in a subject or organism.

For example, the siNA molecules can be administered to a subject or can be administered to other appropriate cells evident to those skilled in the art, individually or in combination with one or more drugs under conditions suitable for the treatment.

In a further embodiment, the siNA molecules can be used in combination with other known treatments to prevent or treat diabetes (type I and/or type II), atherosclerosis, cancer, obesity, and viral infection in a subject or organism. For example, the described molecules could be used in combination with one or more known compounds, treatments, or procedures to prevent or treat diabetes (type I and/or type II), atherosclerosis, cancer, obesity, and viral infection in a subject or organism as are known in the art.

In one embodiment, the invention features an expression vector comprising a nucleic acid sequence encoding at least one siNA molecule of the invention, in a manner which allows expression of the siNA molecule. For example, the vector can contain sequence(s) encoding both strands of an siNA molecule comprising a duplex. The vector can also contain sequence(s) encoding a single nucleic acid molecule that is self-complementary and thus forms an siNA molecule. Non-limiting examples of such expression vectors are described in Paul et al., 2002, Nature Biotechnology, 19, 505; Miyagishi and Taira, 2002, Nature Biotechnology, 19, 497; Lee et al., 2002, Nature Biotechnology, 19, 500; and Novina et al., 2002, Nature Medicine, advance online publication doi:10.1038/nm725.

In another embodiment, the invention features a mammalian cell, for example, a human cell, including an expression vector of the invention.

In yet another embodiment, the expression vector of the invention comprises a sequence for an siNA molecule having complementarity to a RNA molecule referred to by a Genbank Accession numbers, for example Genbank Accession Nos. shown in Table I.

In one embodiment, an expression vector of the invention comprises a nucleic acid sequence encoding two or more siNA molecules, which can be the same or different.

In another aspect of the invention, siNA molecules that interact with target RNA molecules and down-regulate gene encoding target RNA molecules (for example target RNA molecules referred to by Genbank Accession numbers herein) are expressed from transcription units inserted into DNA or RNA vectors. The recombinant vectors can be DNA plasmids or viral vectors. siNA expressing viral vectors can be constructed based on, but not limited to, adeno-associated virus, retrovirus, adenovirus, or alphavirus. The recombinant vectors capable of expressing the siNA molecules can be delivered as described herein, and persist in target cells. Alternatively, viral vectors can be used that provide for transient expression of siNA molecules. Such vectors can be repeatedly administered as necessary. Once expressed, the siNA molecules bind and down-regulate gene function or expression via RNA interference (RNAi). Delivery of siNA expressing vectors can be systemic, such as by intravenous or intramuscular administration, by administration to target cells ex-planted from a subject followed by reintroduction into the subject, or by any other means that would allow for introduction into the desired target cell.

By “vectors” is meant any nucleic acid- and/or viral-based technique used to deliver a desired nucleic acid.

Other features and advantages of the invention will be apparent from the following description of the preferred embodiments thereof, and from the claims.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows a non-limiting example of a scheme for the synthesis of siNA molecules. The complementary siNA sequence strands, strand 1 and strand 2, are synthesized in tandem and are connected by a cleavable linkage, such as a nucleotide succinate or abasic succinate, which can be the same or different from the cleavable linker used for solid phase synthesis on a solid support. The synthesis can be either solid phase or solution phase, in the example shown, the synthesis is a solid phase synthesis. The synthesis is performed such that a protecting group, such as a dimethoxytrityl group, remains intact on the terminal nucleotide of the tandem oligonucleotide. Upon cleavage and deprotection of the oligonucleotide, the two siNA strands spontaneously hybridize to form an siNA duplex, which allows the purification of the duplex by utilizing the properties of the terminal protecting group, for example by applying a trityl on purification method wherein only duplexes/oligonucleotides with the terminal protecting group are isolated.

FIG. 2 shows a MALDI-TOF mass spectrum of a purified siNA duplex synthesized by a method of the invention. The two peaks shown correspond to the predicted mass of the separate siNA sequence strands. This result demonstrates that the siNA duplex generated from tandem synthesis can be purified as a single entity using a simple trityl-on purification methodology.

FIG. 3 shows a non-limiting proposed mechanistic representation of target RNA degradation involved in RNAi. Double-stranded RNA (dsRNA), which is generated by RNA-dependent RNA polymerase (RdRP) from foreign single-stranded RNA, for example viral, transposon, or other exogenous RNA, activates the DICER enzyme that in turn generates siNA duplexes. Alternately, synthetic or expressed siNA can be introduced directly into a cell by appropriate means. An active siNA complex forms which recognizes a target RNA, resulting in degradation of the target RNA by the RISC endonuclease complex or in the synthesis of additional RNA by RNA-dependent RNA polymerase (RdRP), which can activate DICER and result in additional siNA molecules, thereby amplifying the RNAi response.

FIG. 4A-F shows non-limiting examples of chemically modified siNA constructs of the present invention. In the figure, N stands for any nucleotide (adenosine, guanosine, cytosine, uridine, or optionally thymidine, for example thymidine can be substituted in the overhanging regions designated by parenthesis (N N). Various modifications are shown for the sense and antisense strands of the siNA constructs. The antisense strand of constructs A-F comprise sequence complementary to any target nucleic acid sequence of the invention. Furthermore, when a glyceryl moiety (L) is present at the 3′-end of the antisense strand for any construct shown in FIG. 4 A-F, the modified internucleotide linkage is optional.

FIG. 4A: The sense strand comprises 21 nucleotides wherein the two terminal 3′-nucleotides are optionally base paired and wherein all nucleotides present are ribonucleotides except for (N N) nucleotides, which can comprise ribonucleotides, deoxynucleotides, universal bases, or other chemical modifications described herein. The antisense strand comprises 21 nucleotides, optionally having a 3′-terminal glyceryl moiety wherein the two terminal 3′-nucleotides are optionally complementary to the target RNA sequence, and wherein all nucleotides present are ribonucleotides except for (N N) nucleotides, which can comprise ribonucleotides, deoxynucleotides, universal bases, or other chemical modifications described herein. A modified internucleotide linkage, such as a phosphorothioate, phosphorodithioate or other modified internucleotide linkage as described herein, shown as “s”, optionally connects the (N N) nucleotides in the antisense strand.

FIG. 4B: The sense strand comprises 21 nucleotides wherein the two terminal 3′-nucleotides are optionally base paired and wherein all pyrimidine nucleotides that may be present are 2′deoxy-2′-fluoro modified nucleotides and all purine nucleotides that may be present are 2′-O-methyl modified nucleotides except for (N N) nucleotides, which can comprise ribonucleotides, deoxynucleotides, universal bases, or other chemical modifications described herein. The antisense strand comprises 21 nucleotides, optionally having a 3′-terminal glyceryl moiety and wherein the two terminal 3′-nucleotides are optionally complementary to the target RNA sequence, and wherein all pyrimidine nucleotides that may be present are 2′-deoxy-2′-fluoro modified nucleotides and all purine nucleotides that may be present are 2′-O-methyl modified nucleotides except for (N N) nucleotides, which can comprise ribonucleotides, deoxynucleotides, universal bases, or other chemical modifications described herein. A modified internucleotide linkage, such as a phosphorothioate, phosphorodithioate or other modified internucleotide linkage as described herein, shown as “s”, optionally connects the (N N) nucleotides in the sense and antisense strand.

FIG. 4C: The sense strand comprises 21 nucleotides having 5′- and 3′-terminal cap moieties wherein the two terminal 3′-nucleotides are optionally base paired and wherein all pyrimidine nucleotides that may be present are 2′-O-methyl or 2′-deoxy-2′-fluoro modified nucleotides except for (N N) nucleotides, which can comprise ribonucleotides, deoxynucleotides, universal bases, or other chemical modifications described herein. The antisense strand comprises 21 nucleotides, optionally having a 3′-terminal glyceryl moiety and wherein the two terminal 3′-nucleotides are optionally complementary to the target RNA sequence, and wherein all pyrimidine nucleotides that may be present are 2′-deoxy-2′-fluoro modified nucleotides except for (N N) nucleotides, which can comprise ribonucleotides, deoxynucleotides, universal bases, or other chemical modifications described herein. A modified internucleotide linkage, such as a phosphorothioate, phosphorodithioate or other modified internucleotide linkage as described herein, shown as “s”, optionally connects the (N N) nucleotides in the antisense strand.

FIG. 4D: The sense strand comprises 21 nucleotides having 5′- and 3′-terminal cap moieties wherein the two terminal 3′-nucleotides are optionally base paired and wherein all pyrimidine nucleotides that may be present are 2′-deoxy-2′-fluoro modified nucleotides except for (N N) nucleotides, which can comprise ribonucleotides, deoxynucleotides, universal bases, or other chemical modifications described herein and wherein and all purine nucleotides that may be present are 2′-deoxy nucleotides. The antisense strand comprises 21 nucleotides, optionally having a 3′-terminal glyceryl moiety and wherein the two terminal 3′-nucleotides are optionally complementary to the target RNA sequence, wherein all pyrimidine nucleotides that may be present are 2′-deoxy-2′-fluoro modified nucleotides and all purine nucleotides that may be present are 2′-O-methyl modified nucleotides except for (N N) nucleotides, which can comprise ribonucleotides, deoxynucleotides, universal bases, or other chemical modifications described herein. A modified internucleotide linkage, such as a phosphorothioate, phosphorodithioate or other modified internucleotide linkage as described herein, shown as “s”, optionally connects the (N N) nucleotides in the antisense strand.

FIG. 4E: The sense strand comprises 21 nucleotides having 5′- and 3′-terminal cap moieties wherein the two terminal 3′-nucleotides are optionally base paired and wherein all pyrimidine nucleotides that may be present are 2′-deoxy-2′-fluoro modified nucleotides except for (N N) nucleotides, which can comprise ribonucleotides, deoxynucleotides, universal bases, or other chemical modifications described herein. The antisense strand comprises 21 nucleotides, optionally having a 3′-terminal glyceryl moiety and wherein the two terminal 3′-nucleotides are optionally complementary to the target RNA sequence, and wherein all pyrimidine nucleotides that may be present are 2′-deoxy-2′-fluoro modified nucleotides and all purine nucleotides that may be present are 2′-O-methyl modified nucleotides except for (N N) nucleotides, which can comprise ribonucleotides, deoxynucleotides, universal bases, or other chemical modifications described herein. A modified internucleotide linkage, such as a phosphorothioate, phosphorodithioate or other modified internucleotide linkage as described herein, shown as “s”, optionally connects the (N N) nucleotides in the antisense strand.

FIG. 4F: The sense strand comprises 21 nucleotides having 5′- and 3′-terminal cap moieties wherein the two terminal 3′-nucleotides are optionally base paired and wherein all pyrimidine nucleotides that may be present are 2′-deoxy-2′-fluoro modified nucleotides except for (N N) nucleotides, which can comprise ribonucleotides, deoxynucleotides, universal bases, or other chemical modifications described herein and wherein and all purine nucleotides that may be present are 2′-deoxy nucleotides. The antisense strand comprises 21 nucleotides, optionally having a 3′-terminal glyceryl moiety and wherein the two terminal 3′-nucleotides are optionally complementary to the target RNA sequence, and having one 3′-terminal phosphorothioate internucleotide linkage and wherein all pyrimidine nucleotides that may be present are 2′-deoxy-2′-fluoro modified nucleotides and all purine nucleotides that may be present are 2′-deoxy nucleotides except for (N N) nucleotides, which can comprise ribonucleotides, deoxynucleotides, universal bases, or other chemical modifications described herein. A modified internucleotide linkage, such as a phosphorothioate, phosphorodithioate or other modified internucleotide linkage as described herein, shown as “s”, optionally connects the (N N) nucleotides in the antisense strand.

FIG. 5A-F shows non-limiting examples of specific chemically modified siNA sequences of the invention. A-F applies the chemical modifications described in FIG. 4A-F to a SCD siNA sequence. Such chemical modifications can be applied to any SCD sequence and/or SCD polymorphism sequence.

FIG. 6 shows non-limiting examples of different siNA constructs of the invention. The examples shown (constructs 1, 2, and 3) have 19 representative base pairs; however, different embodiments of the invention include any number of base pairs described herein. Bracketed regions represent nucleotide overhangs, for example, comprising about 1, 2, 3, or 4 nucleotides in length, preferably about 2 nucleotides. Constructs 1 and 2 can be used independently for RNAi activity. Construct 2 can comprise a polynucleotide or non-nucleotide linker, which can optionally be designed as a biodegradable linker. In one embodiment, the loop structure shown in construct 2 can comprise a biodegradable linker that results in the formation of construct I in vivo and/or in vitro. In another example, construct 3 can be used to generate construct 2 under the same principle wherein a linker is used to generate the active siNA construct 2 in vivo and/or in vitro, which can optionally utilize another biodegradable linker to generate the active siNA construct I in vivo and/or in vitro. As such, the stability and/or activity of the siNA constructs can be modulated based on the design of the siNA construct for use in vivo or in vitro and/or in vitro.

FIG. 7A-C is a diagrammatic representation of a scheme utilized in generating an expression cassette to generate siNA hairpin constructs.

FIG. 7A: A DNA oligomer is synthesized with a 5′-restriction site (R1) sequence followed by a region having sequence identical (sense region of siNA) to a predetermined SCD target sequence, wherein the sense region comprises, for example, about 19, 20, 21, or 22 nucleotides (N) in length, which is followed by a loop sequence of defined sequence (X), comprising, for example, about 3 to about 10 nucleotides.

FIG. 7B: The synthetic construct is then extended by DNA polymerase to generate a hairpin structure having self-complementary sequence that will result in an siNA transcript having specificity for a SCD target sequence and having self-complementary sense and antisense regions.

FIG. 7C: The construct is heated (for example to about 95° C.) to linearize the sequence, thus allowing extension of a complementary second DNA strand using a primer to the 3′-restriction sequence of the first strand. The double-stranded DNA is then inserted into an appropriate vector for expression in cells. The construct can be designed such that a 3′-terminal nucleotide overhang results from the transcription, for example, by engineering restriction sites and/or utilizing a poly-U termination region as described in Paul et al., 2002, Nature Biotechnology, 29, 505-508.

FIG. 8A-C is a diagrammatic representation of a scheme utilized in generating an expression cassette to generate double-stranded siNA constructs.

FIG. 8A: A DNA oligomer is synthesized with a 5′-restriction (R1) site sequence followed by a region having sequence identical (sense region of siNA) to a predetermined SCD target sequence, wherein the sense region comprises, for example, about 19, 20, 21, or 22 nucleotides (N) in length, and which is followed by a 3′-restriction site (R2) which is adjacent to a loop sequence of defined sequence (X).

FIG. 8B: The synthetic construct is then extended by DNA polymerase to generate a hairpin structure having self-complementary sequence.

FIG. 8C: The construct is processed by restriction enzymes specific to R1 and R2 to generate a double-stranded DNA which is then inserted into an appropriate vector for expression in cells. The transcription cassette is designed such that a U6 promoter region flanks each side of the dsDNA which generates the separate sense and antisense strands of the siNA. Poly T termination sequences can be added to the constructs to generate U overhangs in the resulting transcript.

FIG. 9A-E is a diagrammatic representation of a method used to determine target sites for siNA mediated RNAi within a particular target nucleic acid sequence, such as messenger RNA.

FIG. 9A: A pool of siNA oligonucleotides are synthesized wherein the antisense region of the siNA constructs has complementarity to target sites across the target nucleic acid sequence, and wherein the sense region comprises sequence complementary to the antisense region of the siNA.

FIGS. 9B&C: (FIG. 9B) The sequences are pooled and are inserted into vectors such that (FIG. 9C) transfection of a vector into cells results in the expression of the siNA.

FIG. 9D: Cells are sorted based on phenotypic change that is associated with modulation of the target nucleic acid sequence.

FIG. 9E: The siNA is isolated from the sorted cells and is sequenced to identify efficacious target sites within the target nucleic acid sequence.

FIG. 10 shows non-limiting examples of different stabilization chemistries (1-10) that can be used, for example, to stabilize the 3′-end of siNA sequences of the invention, including (1) [3-3′]-inverted deoxyribose; (2) deoxyribonucleotide; (3) [5′-3′]-3′-deoxyribonucleotide; (4) [5′-3′]-ribonucleotide; (5) [5′-3′]-3′-O-methyl ribonucleotide; (6) 3′-glyceryl; (7) [3′-5′]-3′-deoxyribonucleotide; (8) [3′-3′]-deoxyribonucleotide; (9) [5′-2′]-deoxyribonucleotide; and (10) [5-3′]-dideoxyribonucleotide. In addition to modified and unmodified backbone chemistries indicated in the figure, these chemistries can be combined with different backbone modifications as described herein, for example, backbone modifications having Formula I. In addition, the 2′-deoxy nucleotide shown 5′ to the terminal modifications shown can be another modified or unmodified nucleotide or non-nucleotide described herein, for example modifications having any of Formulae I-VII or any combination thereof.

FIG. 11 shows a non-limiting example of a strategy used to identify chemically modified siNA constructs of the invention that are nuclease resistance while preserving the ability to mediate RNAi activity. Chemical modifications are introduced into the siNA construct based on educated design parameters (e.g. introducing 2′-modifications, base modifications, backbone modifications, terminal cap modifications etc). The modified construct in tested in an appropriate system (e.g. human serum for nuclease resistance, shown, or an animal model for PK/delivery parameters). In parallel, the siNA construct is tested for RNAi activity, for example in a cell culture system such as a luciferase reporter assay). Lead siNA constructs are then identified which possess a particular characteristic while maintaining RNAi activity, and can be further modified and assayed once again. This same approach can be used to identify siNA-conjugate molecules with improved pharmacokinetic profiles, delivery, and RNAi activity.

FIG. 12 shows non-limiting examples of phosphorylated siNA molecules of the invention, including linear and duplex constructs and asymmetric derivatives thereof.

FIG. 13 shows non-limiting examples of chemically modified terminal phosphate groups of the invention.

FIG. 14A shows a non-limiting example of methodology used to design self complementary DFO constructs utilizing palindrome and/or repeat nucleic acid sequences that are identified in a target nucleic acid sequence. (i) A palindrome or repeat sequence is identified in a nucleic acid target sequence. (ii) A sequence is designed that is complementary to the target nucleic acid sequence and the palindrome sequence. (iii) An inverse repeat sequence of the non-palindrome/repeat portion of the complementary sequence is appended to the 3′-end of the complementary sequence to generate a self complementary DFO molecule comprising sequence complementary to the nucleic acid target. (iv) The DFO molecule can self-assemble to form a double-stranded oligonucleotide. FIG. 14B shows a non-limiting representative example of a duplex forming oligonucleotide sequence. FIG. 14C shows a non-limiting example of the self assembly schematic of a representative duplex forming oligonucleotide sequence. FIG. 14D shows a non-limiting example of the self assembly schematic of a representative duplex forming oligonucleotide sequence followed by interaction with a target nucleic acid sequence resulting in modulation of gene expression.

FIG. 15 shows a non-limiting example of the design of self complementary DFO constructs utilizing palindrome and/or repeat nucleic acid sequences that are incorporated into the DFO constructs that have sequence complementary to any target nucleic acid sequence of interest. Incorporation of these palindrome/repeat sequences allow the design of DFO constructs that form duplexes in which each strand is capable of mediating modulation of target gene expression, for example by RNAi. First, the target sequence is identified. A complementary sequence is then generated in which nucleotide or non-nucleotide modifications (shown as X or Y) are introduced into the complementary sequence that generate an artificial palindrome (shown as XYXYXY in the Figure). An inverse repeat of the non-palindrome/repeat complementary sequence is appended to the 3′-end of the complementary sequence to generate a self complementary DFO comprising sequence complementary to the nucleic acid target. The DFO can self-assemble to form a double-stranded oligonucleotide.

FIG. 16 shows non-limiting examples of multifunctional siNA molecules of the invention comprising two separate polynucleotide sequences that are each capable of mediating RNAi directed cleavage of differing target nucleic acid sequences. FIG. 16A shows a non-limiting example of a multifunctional siNA molecule having a first region that is complementary to a first target nucleic acid sequence (complementary region 1) and a second region that is complementary to a second target nucleic acid sequence (complementary region 2), wherein the first and second complementary regions are situated at the 3′-ends of each polynucleotide sequence in the multifunctional siNA. The dashed portions of each polynucleotide sequence of the multifunctional siNA construct have complementarity with regard to corresponding portions of the siNA duplex, but do not have complementarity to the target nucleic acid sequences. FIG. 16B shows a non-limiting example of a multifunctional siNA molecule having a first region that is complementary to a first target nucleic acid sequence (complementary region 1) and a second region that is complementary to a second target nucleic acid sequence (complementary region 2), wherein the first and second complementary regions are situated at the 5′-ends of each polynucleotide sequence in the multifunctional siNA. The dashed portions of each polynucleotide sequence of the multifunctional siNA construct have complementarity with regard to corresponding portions of the siNA duplex, but do not have complementarity to the target nucleic acid sequences.

FIG. 17 shows non-limiting examples of multifunctional siNA molecules of the invention comprising a single polynucleotide sequence comprising distinct regions that are each capable of mediating RNAi directed cleavage of differing target nucleic acid sequences. FIG. 17A shows a non-limiting example of a multifunctional siNA molecule having a first region that is complementary to a first target nucleic acid sequence (complementary region 1) and a second region that is complementary to a second target nucleic acid sequence (complementary region 2), wherein the second complementary region is situated at the 3′-end of the polynucleotide sequence in the multifunctional siNA. The dashed portions of each polynucleotide sequence of the multifunctional siNA construct have complementarity with regard to corresponding portions of the siNA duplex, but do not have complementarity to the target nucleic acid sequences. FIG. 17B shows a non-limiting example of a multifunctional siNA molecule having a first region that is complementary to a first target nucleic acid sequence (complementary region 1) and a second region that is complementary to a second target nucleic acid sequence (complementary region 2), wherein the first complementary region is situated at the 5′-end of the polynucleotide sequence in the multifunctional siNA. The dashed portions of each polynucleotide sequence of the multifunctional siNA construct have complementarity with regard to corresponding portions of the siNA duplex, but do not have complementarity to the target nucleic acid sequences. In one embodiment, these multifunctional siNA constructs are processed in vivo or in vitro to generate multifunctional siNA constructs as shown in FIG. 16.

FIG. 18 shows non-limiting examples of multifunctional siNA molecules of the invention comprising two separate polynucleotide sequences that are each capable of mediating RNAi directed cleavage of differing target nucleic acid sequences and wherein the multifunctional siNA construct further comprises a self complementary, palindrome, or repeat region, thus enabling shorter bifunctional siNA constructs that can mediate RNA interference against differing target nucleic acid sequences. FIG. 18A shows a non-limiting example of a multifunctional siNA molecule having a first region that is complementary to a first target nucleic acid sequence (complementary region 1) and a second region that is complementary to a second target nucleic acid sequence (complementary region 2), wherein the first and second complementary regions are situated at the 3′-ends of each polynucleotide sequence in the multifunctional siNA, and wherein the first and second complementary regions further comprise a self complementary, palindrome, or repeat region. The dashed portions of each polynucleotide sequence of the multifunctional siNA construct have complementarity with regard to corresponding portions of the siNA duplex, but do not have complementarity to the target nucleic acid sequences. FIG. 18B shows a non-limiting example of a multifunctional siNA molecule having a first region that is complementary to a first target nucleic acid sequence (complementary region 1) and a second region that is complementary to a second target nucleic acid sequence (complementary region 2), wherein the first and second complementary regions are situated at the 5′-ends of each polynucleotide sequence in the multifunctional siNA, and wherein the first and second complementary regions further comprise a self complementary, palindrome, or repeat region. The dashed portions of each polynucleotide sequence of the multifunctional siNA construct have complementarity with regard to corresponding portions of the siNA duplex, but do not have complementarity to the target nucleic acid sequences.

FIG. 19 shows non-limiting examples of multifunctional siNA molecules of the invention comprising a single polynucleotide sequence comprising distinct regions that are each capable of mediating RNAi directed cleavage of differing target nucleic acid sequences and wherein the multifunctional siNA construct further comprises a self complementary, palindrome, or repeat region, thus enabling shorter bifunctional siNA constructs that can mediate RNA interference against differing target nucleic acid sequences. FIG. 19A shows a non-limiting example of a multifunctional siNA molecule having a first region that is complementary to a first target nucleic acid sequence (complementary region 1) and a second region that is complementary to a second target nucleic acid sequence (complementary region 2), wherein the second complementary region is situated at the 3′-end of the polynucleotide sequence in the multifunctional siNA, and wherein the first and second complementary regions further comprise a self complementary, palindrome, or repeat region. The dashed portions of each polynucleotide sequence of the multifunctional siNA construct have complementarity with regard to corresponding portions of the siNA duplex, but do not have complementarity to the target nucleic acid sequences. FIG. 19B shows a non-limiting example of a multifunctional siNA molecule having a first region that is complementary to a first target nucleic acid sequence (complementary region 1) and a second region that is complementary to a second target nucleic acid sequence (complementary region 2), wherein the first complementary region is situated at the 5′-end of the polynucleotide sequence in the multifunctional siNA, and wherein the first and second complementary regions further comprise a self complementary, palindrome, or repeat region. The dashed portions of each polynucleotide sequence of the multifunctional siNA construct have complementarity with regard to corresponding portions of the siNA duplex, but do not have complementarity to the target nucleic acid sequences. In one embodiment, these multifunctional siNA constructs are processed in vivo or in vitro to generate multifunctional siNA constructs as shown in FIG. 18.

FIG. 20 shows a non-limiting example of how multifunctional siNA molecules of the invention can target two separate target nucleic acid molecules, such as separate RNA molecules encoding differing proteins, for example, a cytokine and its corresponding receptor, differing viral strains, a virus and a cellular protein involved in viral infection or replication, or differing proteins involved in a common or divergent biologic pathway that is implicated in the maintenance of progression of disease. Each strand of the multifunctional siNA construct comprises a region having complementarity to separate target nucleic acid molecules. The multifunctional siNA molecule is designed such that each strand of the siNA can be utilized by the RISC complex to initiate RNA interference mediated cleavage of its corresponding target. These design parameters can include destabilization of each end of the siNA construct (see for example Schwarz et al., 2003, Cell, 115, 199-208). Such destabilization can be accomplished for example by using guanosine-cytidine base pairs, alternate base pairs (e.g., wobbles), or destabilizing chemically modified nucleotides at terminal nucleotide positions as is known in the art.

FIG. 21 shows a non-limiting example of how multifunctional siNA molecules of the invention can target two separate target nucleic acid sequences within the same target nucleic acid molecule, such as alternate coding regions of a RNA, coding and non-coding regions of a RNA, or alternate splice variant regions of a RNA. Each strand of the multifunctional siNA construct comprises a region having complementarity to the separate regions of the target nucleic acid molecule. The multifunctional siNA molecule is designed such that each strand of the siNA can be utilized by the RISC complex to initiate RNA interference mediated cleavage of its corresponding target region. These design parameters can include destabilization of each end of the siNA construct (see for example Schwarz et al., 2003, Cell, 115, 199-208). Such destabilization can be accomplished for example by using guanosine-cytidine base pairs, alternate base pairs (e.g., wobbles), or destabilizing chemically modified nucleotides at terminal nucleotide positions as is known in the art.

FIG. 22 shows a non-limiting example of reduction of SCD mRNA in A549 cells mediated by chemically modified siNAs that target SCD mRNA. A549 cells were transfected with 0.25 ug/well of lipid complexed with 25 nM siNA. Active siNA constructs comprising various stabilization chemistries (see Tables III and IV) were compared to untreated cells, a matched chemistry irrelevant siNA control construct (IC; 32072/32075), and cells transfected with lipid alone (transfection control). As shown in the figure, the siNA constructs significantly reduce SCD RNA expression.

DETAILED DESCRIPTION OF THE INVENTION Mechanism of Action of Nucleic Acid Molecules of the Invention

The discussion that follows discusses the proposed mechanism of RNA interference mediated by short interfering RNA as is presently known, and is not meant to be limiting and is not an admission of prior art. Applicant demonstrates herein that chemically modified short interfering nucleic acids possess similar or improved capacity to mediate RNAi as do siRNA molecules and are expected to possess improved stability and activity in vivo; therefore, this discussion is not meant to be limiting only to siRNA and can be applied to siNA as a whole. By “improved capacity to mediate RNAi” or “improved RNAi activity” is meant to include RNAi activity measured in vitro and/or in vivo where the RNAi activity is a reflection of both the ability of the siNA to mediate RNAi and the stability of the siNAs of the invention. In this invention, the product of these activities can be increased in vitro and/or in vivo compared to an all RNA siRNA or an siNA containing a plurality of ribonucleotides. In some cases, the activity or stability of the siNA molecule can be decreased (i.e., less than ten-fold), but the overall activity of the siNA molecule is enhanced in vitro and/or in vivo.

RNA interference refers to the process of sequence specific post-transcriptional gene silencing in animals mediated by short interfering RNAs (siRNAs) (Fire et al., 1998, Nature, 391, 806). The corresponding process in plants is commonly referred to as post-transcriptional gene silencing or RNA silencing and is also referred to as quelling in fungi. The process of post-transcriptional gene silencing is thought to be an evolutionarily-conserved cellular defense mechanism used to prevent the expression of foreign genes which is commonly shared by diverse flora and phyla (Fire et al., 1999, Trends Genet., 15, 358). Such protection from foreign gene expression may have evolved in response to the production of double-stranded RNAs (dsRNAs) derived from viral infection or the random integration of transposon elements into a host genome via a cellular response that specifically destroys homologous single-stranded RNA or viral genomic RNA. The presence of dsRNA in cells triggers the RNAi response though a mechanism that has yet to be fully characterized. This mechanism appears to be different from the interferon response that results from dsRNA-mediated activation of protein kinase PKR and 2′,5′-oligoadenylate synthetase resulting in non-specific cleavage of mRNA by ribonuclease L.

The presence of long dsRNAs in cells stimulates the activity of a ribonuclease III enzyme referred to as Dicer. Dicer is involved in the processing of the dsRNA into short pieces of dsRNA known as short interfering RNAs (siRNAs) (Berstein et al., 2001, Nature, 409, 363). Short interfering RNAs derived from Dicer activity are typically about 21 to about 23 nucleotides in length and comprise about 19 base pair duplexes. Dicer has also been implicated in the excision of 21- and 22-nucleotide small temporal RNAs (stRNAs) from precursor RNA of conserved structure that are implicated in translational control (Hutvagner et al., 2001, Science, 293, 834). The RNAi response also features an endonuclease complex containing an siRNA, commonly referred to as an RNA-induced silencing complex (RISC), which mediates cleavage of single-stranded RNA having sequence homologous to the siRNA. Cleavage of the target RNA takes place in the middle of the region complementary to the guide sequence of the siRNA duplex (Elbashir et al., 2001, Genes Dev., 15, 188). In addition, RNA interference can also involve small RNA (e.g., micro-RNA or miRNA) mediated gene silencing, presumably though cellular mechanisms that regulate chromatin structure and thereby prevent transcription of target gene sequences (see for example Allshire, 2002, Science, 297, 1818-1819; Volpe et al., 2002, Science, 297, 1833-1837; Jenuwein, 2002, Science, 297, 2215-2218; and Hall et al., 2002, Science, 297, 2232-2237). As such, siNA molecules of the invention can be used to mediate gene silencing via interaction with RNA transcripts or alternately by interaction with particular gene sequences, wherein such interaction results in gene silencing either at the transcriptional level or post-transcriptional level.

RNAi has been studied in a variety of systems. Fire et al., 1998, Nature, 391, 806, were the first to observe RNAi in C. elegans. Wianny and Goetz, 1999, Nature Cell Biol., 2, 70, describe RNAi mediated by dsRNA in mouse embryos. Hammond et al., 2000, Nature, 404, 293, describe RNAi in Drosophila cells transfected with dsRNA. Elbashir et al., 2001, Nature, 411, 494, describe RNAi induced by introduction of duplexes of synthetic 21-nucleotide RNAs in cultured mammalian cells including human embryonic kidney and HeLa cells. Recent work in Drosophila embryonic lysates has revealed certain requirements for siRNA length, structure, chemical composition, and sequence that are essential to mediate efficient RNAi activity. These studies have shown that 21 nucleotide siRNA duplexes are most active when containing two 2-nucleotide 3′-terminal nucleotide overhangs. Furthermore, substitution of one or both siRNA strands with 2′-deoxy or 2′-O-methyl nucleotides abolishes RNAi activity, whereas substitution of 3′-terminal siRNA nucleotides with deoxy nucleotides was shown to be tolerated. Mismatch sequences in the center of the siRNA duplex were also shown to abolish RNAi activity. In addition, these studies also indicate that the position of the cleavage site in the target RNA is defined by the 5′-end of the siRNA guide sequence rather than the 3′-end (Elbashir et al., 2001, EMBO J., 20, 6877). Other studies have indicated that a 5′-phosphate on the target-complementary strand of an siRNA duplex is required for siRNA activity and that ATP is utilized to maintain the 5′-phosphate moiety on the siRNA (Nykanen et al., 2001, Cell, 107, 309); however, siRNA molecules lacking a 5′-phosphate are active when introduced exogenously, suggesting that 5′-phosphorylation of siRNA constructs may occur in vivo.

Synthesis of Nucleic Acid Molecules

Synthesis of nucleic acids greater than 100 nucleotides in length is difficult using automated methods, and the therapeutic cost of such molecules is prohibitive. In this invention, small nucleic acid motifs (“small” refers to nucleic acid motifs no more than 100 nucleotides in length, preferably no more than 80 nucleotides in length, and most preferably no more than 50 nucleotides in length; e.g., individual siNA oligonucleotide sequences or siNA sequences synthesized in tandem) are preferably used for exogenous delivery. The simple structure of these molecules increases the ability of the nucleic acid to invade targeted regions of protein and/or RNA structure. Exemplary molecules of the instant invention are chemically synthesized, and others can similarly be synthesized.

Oligonucleotides (e.g., certain modified oligonucleotides or portions of oligonucleotides lacking ribonucleotides) are synthesized using protocols known in the art, for example as described in Caruthers et al., 1992, Methods in Enzymology 211, 3-19, Thompson et al., International PCT Publication No. WO 99/54459, Wincott et al., 1995, Nucleic Acids Res. 23, 2677-2684, Wincott et al., 1997, Methods Mol. Bio., 74, 59, Brennan et al., 1998, Biotechnol Bioeng., 61, 3345, and Brennan, U.S. Pat. No. 6,001,311. All of these references are incorporated herein by reference. The synthesis of oligonucleotides makes use of common nucleic acid protecting and coupling groups, such as dimethoxytrityl at the 5′-end, and phosphoramidites at the 3′-end. In a non-limiting example, small scale syntheses are conducted on a 394 Applied Biosystems, Inc. synthesizer using a 0.2 μmol scale protocol with a 2.5 min coupling step for 2′-O-methylated nucleotides and a 45 second coupling step for 2′-deoxy nucleotides or 2′-deoxy-2′-fluoro nucleotides. Table V outlines the amounts and the contact times of the reagents used in the synthesis cycle. Alternatively, syntheses at the 0.2 μmol scale can be performed on a 96-well plate synthesizer, such as the instrument produced by Protogene (Palo Alto, Calif.) with minimal modification to the cycle. A 33-fold excess (60 μL of 0.11 M=6.6 μmol) of 2′-O-methyl phosphoramidite and a 105-fold excess of S-ethyl tetrazole (60 μL of 0.25 M=15 μmol) can be used in each coupling cycle of 2′-O-methyl residues relative to polymer-bound 5′-hydroxyl. A 22-fold excess (40 μL of 0.11 M=4.4 μmol) of deoxy phosphoramidite and a 70-fold excess of S-ethyl tetrazole (40 μL of 0.25 M=10 μmol) can be used in each coupling cycle of deoxy residues relative to polymer-bound 5′-hydroxyl. Average coupling yields on the 394 Applied Biosystems, Inc. synthesizer, determined by colorimetric quantitation of the trityl fractions, are typically 97.5-99%. Other oligonucleotide synthesis reagents for the 394 Applied Biosystems, Inc. synthesizer include the following: detritylation solution is 3% TCA in methylene chloride (ABI); capping is performed with 16% N-methyl imidazole in THF (ABI) and 10% acetic anhydride/10% 2,6-lutidine in THF (ABI); and oxidation solution is 16.9 mM 12, 49 mM pyridine, 9% water in THF (PerSeptive Biosystems, Inc.). Burdick & Jackson Synthesis Grade acetonitrile is used directly from the reagent bottle. S-Ethyltetrazole solution (0.25 M in acetonitrile) is made up from the solid obtained from American International Chemical, Inc. Alternately, for the introduction of phosphorothioate linkages, Beaucage reagent (3H-1,2-benzodithiol-3-one 1,1-dioxide, 0.05 M in acetonitrile) is used.

Deprotection of the DNA-based oligonucleotides is performed as follows: the polymer-bound trityl-on oligoribonucleotide is transferred to a 4 mL glass screw top vial and suspended in a solution of 40% aqueous methylamine (1 mL) at 65° C. for 10 minutes. After cooling to −20° C., the supernatant is removed from the polymer support. The support is washed three times with 1.0 mL of EtOH:MeCN:H2O/3:1:1, vortexed and the supernatant is then added to the first supernatant. The combined supernatants, containing the oligoribonucleotide, are dried to a white powder.

The method of synthesis used for RNA including certain siNA molecules of the invention follows the procedure as described in Usman et al., 1987, J. Am. Chem. Soc., 109, 7845; Scaringe et al., 1990, Nucleic Acids Res., 18, 5433; and Wincott et al., 1995, Nucleic Acids Res. 23, 2677-2684 Wincott et al., 1997, Methods Mol. Bio., 74, 59, and makes use of common nucleic acid protecting and coupling groups, such as dimethoxytrityl at the 5′-end, and phosphoramidites at the 3′-end. In a non-limiting example, small scale syntheses are conducted on a 394 Applied Biosystems, Inc. synthesizer using a 0.2 μmol scale protocol with a 7.5 min coupling step for alkylsilyl protected nucleotides and a 2.5 min coupling step for 2′-O-methylated nucleotides. Table V outlines the amounts and the contact times of the reagents used in the synthesis cycle. Alternatively, syntheses at the 0.2 μmol scale can be done on a 96-well plate synthesizer, such as the instrument produced by Protogene (Palo Alto, Calif.) with minimal modification to the cycle. A 33-fold excess (60 μL of 0.11 M=6.6 μmol) of 2′-O-methyl phosphoramidite and a 75-fold excess of S-ethyl tetrazole (60 μL of 0.25 M=15 μmol) can be used in each coupling cycle of 2′-O-methyl residues relative to polymer-bound 5′-hydroxyl. A 66-fold excess (120 μL of 0.11 M=13.2 μmol) of alkylsilyl (ribo) protected phosphoramidite and a 150-fold excess of S-ethyl tetrazole (120 μL of 0.25 M=30 μmol) can be used in each coupling cycle of ribo residues relative to polymer-bound 5′-hydroxyl. Average coupling yields on the 394 Applied Biosystems, Inc. synthesizer, determined by colorimetric quantitation of the trityl fractions, are typically 97.5-99%. Other oligonucleotide synthesis reagents for the 394 Applied Biosystems, Inc. synthesizer include the following: detritylation solution is 3% TCA in methylene chloride (ABI); capping is performed with 16% N-methyl imidazole in THF (ABI) and 10% acetic anhydride/10% 2,6-lutidine in THF (ABI); oxidation solution is 16.9 mM 12, 49 mM pyridine, 9% water in THF (PerSeptive Biosystems, Inc.). Burdick & Jackson Synthesis Grade acetonitrile is used directly from the reagent bottle. S-Ethyltetrazole solution (0.25 M in acetonitrile) is made up from the solid obtained from American International Chemical, Inc. Alternately, for the introduction of phosphorothioate linkages, Beaucage reagent (3H-1,2-benzodithiol-3-one 1,1-dioxide, 0.05 M in acetonitrile) is used.

Deprotection of the RNA is performed using either a two-pot or one-pot protocol. For the two-pot protocol, the polymer-bound trityl-on oligoribonucleotide is transferred to a 4 mL glass screw top vial and suspended in a solution of 40% aq. methylamine (1 mL) at 65° C. for 10 min. After cooling to −20° C., the supernatant is removed from the polymer support. The support is washed three times with 1.0 mL of EtOH:MeCN: H2O/3:1:1, vortexed and the supernatant is then added to the first supernatant. The combined supernatants, containing the oligoribonucleotide, are dried to a white powder. The base deprotected oligoribonucleotide is resuspended in anhydrous TEA/HF/NMP solution (300 μL of a solution of 1.5 mL N-methylpyrrolidinone, 750 μL TEA and 1 mL TEA-3HF to provide a 1.4 M HF concentration) and heated to 65° C. After 1.5 h, the oligomer is quenched with 1.5 M NH₄HCO₃.

Alternatively, for the one-pot protocol, the polymer-bound trityl-on oligoribonucleotide is transferred to a 4 mL glass screw top vial and suspended in a solution of 33% ethanolic methylamine/DMSO: 1/1 (0.8 mL) at 65° C. for 15 minutes. The vial is brought to room temperature TEA.3HF (0.1 mL) is added and the vial is heated at 65° C. for 15 minutes. The sample is cooled at −20° C. and then quenched with 1.5 M NH₄HCO₃.

For purification of the trityl-on oligomers, the quenched NH₄HCO₃ solution is loaded onto a C-18 containing cartridge that had been prewashed with acetonitrile followed by 50 mM TEAA. After washing the loaded cartridge with water, the RNA is detritylated with 0.5% TFA for 13 minutes. The cartridge is then washed again with water, salt exchanged with 1 M NaCl and washed with water again. The oligonucleotide is then eluted with 30% acetonitrile.

The average stepwise coupling yields are typically >98% (Wincott et al., 1995 Nucleic Acids Res. 23, 2677-2684). Those of ordinary skill in the art will recognize that the scale of synthesis can be adapted to be larger or smaller than the example described above including but not limited to 96-well format.

Alternatively, the nucleic acid molecules of the present invention can be synthesized separately and joined together post-synthetically, for example, by ligation (Moore et al., 1992, Science 256, 9923; Draper et al., International PCT publication No. WO 93/23569; Shabarova et al., 1991, Nucleic Acids Research 19, 4247; Bellon et al., 1997, Nucleosides & Nucleotides, 16, 951; Bellon et al., 1997, Bioconjugate Chem. 8, 204), or by hybridization following synthesis and/or deprotection.

The siNA molecules of the invention can also be synthesized via a tandem synthesis methodology as described in Example 1 herein, wherein both siNA strands are synthesized as a single contiguous oligonucleotide fragment or strand separated by a cleavable linker which is subsequently cleaved to provide separate siNA fragments or strands that hybridize and permit purification of the siNA duplex. The linker can be a polynucleotide linker or a non-nucleotide linker. The tandem synthesis of siNA as described herein can be readily adapted to both multiwell/multiplate synthesis platforms such as 96 well or similarly larger multi-well platforms. The tandem synthesis of siNA as described herein can also be readily adapted to large scale synthesis platforms employing batch reactors, synthesis columns and the like.

An siNA molecule can also be assembled from two distinct nucleic acid strands or fragments wherein one fragment includes the sense region and the second fragment includes the antisense region of the RNA molecule.

The nucleic acid molecules of the present invention can be modified extensively to enhance stability by modification with nuclease resistant groups, for example, 2′-amino, 2′-C-allyl, 2′-fluoro, 2′-O-methyl, 2′-H (for a review see Usman and Cedergren, 1992, TIBS 17, 34; Usman et al., 1994, Nucleic Acids Symp. Ser. 31, 163). siNA constructs can be purified by gel electrophoresis using general methods or can be purified by high pressure liquid chromatography (HPLC; see Wincott et al., supra, the totality of which is hereby incorporated herein by reference) and re-suspended in water.

In another aspect of the invention, siNA molecules of the invention are expressed from transcription units inserted into DNA or RNA vectors. The recombinant vectors can be DNA plasmids or viral vectors. siNA expressing viral vectors can be constructed based on, but not limited to, adeno-associated virus, retrovirus, adenovirus, or alphavirus. The recombinant vectors capable of expressing the siNA molecules can be delivered as described herein, and persist in target cells. Alternatively, viral vectors can be used that provide for transient expression of siNA molecules.

Optimizing Activity of the Nucleic Acid Molecule of the Invention.

Chemically synthesizing nucleic acid molecules with modifications (base, sugar and/or phosphate) can prevent their degradation by serum ribonucleases, which can increase their potency (see e.g., Eckstein et al., International Publication No. WO 92/07065; Perrault et al., 1990 Nature 344, 565; Pieken et al., 1991, Science 253, 314; Usman and Cedergren, 1992, Trends in Biochem. Sci. 17, 334; Usman et al., International Publication No. WO 93/15187; and Rossi et al., International Publication No. WO 91/03162; Sproat, U.S. Pat. No. 5,334,711; Gold et al., U.S. Pat. No. 6,300,074; and Burgin et al., supra; all of which are incorporated by reference herein). All of the above references describe various chemical modifications that can be made to the base, phosphate and/or sugar moieties of the nucleic acid molecules described herein. Modifications that enhance their efficacy in cells, and removal of bases from nucleic acid molecules to shorten oligonucleotide synthesis times and reduce chemical requirements are desired.

There are several examples in the art describing sugar, base and phosphate modifications that can be introduced into nucleic acid molecules with significant enhancement in their nuclease stability and efficacy. For example, oligonucleotides are modified to enhance stability and/or enhance biological activity by modification with nuclease resistant groups, for example, 2′-amino, 2′-C-allyl, 2′-fluoro, 2′-O-methyl, 2′-O-allyl, 2′-H, nucleotide base modifications (for a review see Usman and Cedergren, 1992, TIBS. 17, 34; Usman et al., 1994, Nucleic Acids Symp. Ser. 31, 163; Burgin et al., 1996, Biochemistry, 35, 14090). Sugar modification of nucleic acid molecules have been extensively described in the art (see Eckstein et al., International Publication PCT No. WO 92/07065; Perrault et al. Nature, 1990, 344, 565-568; Pieken et al. Science, 1991, 253, 314-317; Usman and Cedergren, Trends in Biochem. Sci., 1992, 17, 334-339; Usman et al. International Publication PCT No. WO 93/15187; Sproat, U.S. Pat. No. 5,334,711 and Beigelman et al., 1995, J. Biol. Chem., 270, 25702; Beigelman et al., International PCT publication No. WO 97/26270; Beigelman et al., U.S. Pat. No. 5,716,824; Usman et al., U.S. Pat. No. 5,627,053; Woolf et al., International PCT Publication No. WO 98/13526; Thompson et al., U.S. Ser. No. 60/082,404 which was filed on Apr. 20, 1998; Karpeisky et al., 1998, Tetrahedron Lett., 39, 1131; Earnshaw and Gait, 1998, Biopolymers (Nucleic Acid Sciences), 48, 39-55; Verma and Eckstein, 1998, Annu. Rev. Biochem., 67, 99-134; and Burlina et al., 1997, Bioorg. Med. Chem., 5, 1999-2010; all of the references are hereby incorporated in their totality by reference herein). Such publications describe general methods and strategies to determine the location of incorporation of sugar, base and/or phosphate modifications and the like into nucleic acid molecules without modulating catalysis, and are incorporated by reference herein. In view of such teachings, similar modifications can be used as described herein to modify the siNA nucleic acid molecules of the instant invention so long as the ability of siNA to promote RNAi is cells is not significantly inhibited.

While chemical modification of oligonucleotide internucleotide linkages with phosphorothioate, phosphorodithioate, and/or 5′-methylphosphonate linkages improves stability, excessive modifications can cause some toxicity or decreased activity. Therefore, when designing nucleic acid molecules, the amount of these internucleotide linkages should be minimized. The reduction in the concentration of these linkages should lower toxicity, resulting in increased efficacy and higher specificity of these molecules.

Short interfering nucleic acid (siNA) molecules having chemical modifications that maintain or enhance activity are provided. Such a nucleic acid is also generally more resistant to nucleases than an unmodified nucleic acid. Accordingly, the in vitro and/or in vivo activity should not be significantly lowered. In cases in which modulation is the goal, therapeutic nucleic acid molecules delivered exogenously should optimally be stable within cells until translation of the target RNA has been modulated long enough to reduce the levels of the undesirable protein. This period of time varies between hours to days depending upon the disease state. Improvements in the chemical synthesis of RNA and DNA (Wincott et al., 1995, Nucleic Acids Res. 23, 2677; Caruthers et al., 1992, Methods in Enzymology 211, 3-19 (incorporated by reference herein)) have expanded the ability to modify nucleic acid molecules by introducing nucleotide modifications to enhance their nuclease stability, as described above.

In one embodiment, nucleic acid molecules of the invention include one or more (e.g., about 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, or more) G-clamp nucleotides. A G-clamp nucleotide is a modified cytosine analog wherein the modifications confer the ability to hydrogen bond both Watson-Crick and Hoogsteen faces of a complementary guanine within a duplex, see for example Lin and Matteucci, 1998, J. Am. Chem. Soc., 120, 8531-8532. A single G-clamp analog substitution within an oligonucleotide can result in substantially enhanced helical thermal stability and mismatch discrimination when hybridized to complementary oligonucleotides. The inclusion of such nucleotides in nucleic acid molecules of the invention results in both enhanced affinity and specificity to nucleic acid targets, complementary sequences, or template strands. In another embodiment, nucleic acid molecules of the invention include one or more (e.g., about 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, or more) LNA “locked nucleic acid” nucleotides such as a 2′,4′-C methylene bicyclo nucleotide (see for example Wengel et al., International PCT Publication No. WO 00/66604 and WO 99/14226).

In another embodiment, the invention features conjugates and/or complexes of siNA molecules of the invention. Such conjugates and/or complexes can be used to facilitate delivery of siNA molecules into a biological system, such as a cell. The conjugates and complexes provided by the instant invention can impart therapeutic activity by transferring therapeutic compounds across cellular membranes, altering the pharmacokinetics, and/or modulating the localization of nucleic acid molecules of the invention. The present invention encompasses the design and synthesis of novel conjugates and complexes for the delivery of molecules, including, but not limited to, small molecules, lipids, cholesterol, phospholipids, nucleosides, nucleotides, nucleic acids, antibodies, toxins, negatively charged polymers and other polymers, for example proteins, peptides, hormones, carbohydrates, polyethylene glycols, or polyamines, across cellular membranes. In general, the transporters described are designed to be used either individually or as part of a multi-component system, with or without degradable linkers. These compounds are expected to improve delivery and/or localization of nucleic acid molecules of the invention into a number of cell types originating from different tissues, in the presence or absence of serum (see Sullenger and Cech, U.S. Pat. No. 5,854,038). Conjugates of the molecules described herein can be attached to biologically active molecules via linkers that are biodegradable, such as biodegradable nucleic acid linker molecules.

The term “biodegradable linker” as used herein, refers to a nucleic acid or non-nucleic acid linker molecule that is designed as a biodegradable linker to connect one molecule to another molecule, for example, a biologically active molecule to an siNA molecule of the invention or the sense and antisense strands of an siNA molecule of the invention. The biodegradable linker is designed such that its stability can be modulated for a particular purpose, such as delivery to a particular tissue or cell type. The stability of a nucleic acid-based biodegradable linker molecule can be modulated by using various chemistries, for example combinations of ribonucleotides, deoxyribonucleotides, and chemically modified nucleotides, such as 2′-O-methyl, 2′-fluoro, 2′-amino, 2′-O-amino, 2′-C-allyl, 2′-O-allyl, and other 2′-modified or base modified nucleotides. The biodegradable nucleic acid linker molecule can be a dimer, trimer, tetramer or longer nucleic acid molecule, for example, an oligonucleotide of about 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, or 20 nucleotides in length, or can comprise a single nucleotide with a phosphorus-based linkage, for example, a phosphoramidate or phosphodiester linkage. The biodegradable nucleic acid linker molecule can also comprise nucleic acid backbone, nucleic acid sugar, or nucleic acid base modifications.

The term “biodegradable” as used herein, refers to degradation in a biological system, for example, enzymatic degradation or chemical degradation.

The term “biologically active molecule” as used herein refers to compounds or molecules that are capable of eliciting or modifying a biological response in a system. Non-limiting examples of biologically active siNA molecules either alone or in combination with other molecules contemplated by the instant invention include therapeutically active molecules such as antibodies, cholesterol, hormones, antivirals, peptides, proteins, chemotherapeutics, small molecules, vitamins, co-factors, nucleosides, nucleotides, oligonucleotides, enzymatic nucleic acids, antisense nucleic acids, triplex forming oligonucleotides, 2,5-A chimeras, siNA, dsRNA, allozymes, aptamers, decoys and analogs thereof. Biologically active molecules of the invention also include molecules capable of modulating the pharmacokinetics and/or pharmacodynamics of other biologically active molecules, for example, lipids and polymers such as polyamines, polyamides, polyethylene glycol and other polyethers.

The term “phospholipid” as used herein, refers to a hydrophobic molecule comprising at least one phosphorus group. For example, a phospholipid can comprise a phosphorus-containing group and saturated or unsaturated alkyl group, optionally substituted with OH, COOH, oxo, anine, or substituted or unsubstituted aryl groups.

Therapeutic nucleic acid molecules (e.g., siNA molecules) delivered exogenously optimally are stable within cells until reverse transcription of the RNA has been modulated long enough to reduce the levels of the RNA transcript. The nucleic acid molecules are resistant to nucleases in order to function as effective intracellular therapeutic agents. Improvements in the chemical synthesis of nucleic acid molecules described in the instant invention and in the art have expanded the ability to modify nucleic acid molecules by introducing nucleotide modifications to enhance their nuclease stability as described above.

In yet another embodiment, siNA molecules having chemical modifications that maintain or enhance enzymatic activity of proteins involved in RNAi are provided. Such nucleic acids are also generally more resistant to nucleases than unmodified nucleic acids. Thus, in vitro and/or in vivo the activity should not be significantly lowered.

Use of the nucleic acid-based molecules of the invention will lead to better treatments by affording the possibility of combination therapies (e.g., multiple siNA molecules targeted to different genes; nucleic acid molecules coupled with known small molecule modulators; or intermittent treatment with combinations of molecules, including different motifs and/or other chemical or biological molecules). The treatment of subjects with siNA molecules can also include combinations of different types of nucleic acid molecules, such as enzymatic nucleic acid molecules (ribozymes), allozymes, antisense, 2,5-A oligoadenylate, decoys, and aptamers.

In another aspect an siNA molecule of the invention comprises one or more 5′ and/or a 3′-cap structure, for example, on only the sense siNA strand, the antisense siNA strand, or both siNA strands.

By “cap structure” is meant chemical modifications, which have been incorporated at either terminus of the oligonucleotide (see, for example, Adamic et al., U.S. Pat. No. 5,998,203, incorporated by reference herein). These terminal modifications protect the nucleic acid molecule from exonuclease degradation, and may help in delivery and/or localization within a cell. The cap may be present at the 5′-terminus (5′-cap) or at the 3′-terminal (3′-cap) or may be present on both termini. In non-limiting examples, the 5′-cap includes, but is not limited to, glyceryl, inverted deoxy abasic residue (moiety); 4′,5′-methylene nucleotide; 1-(beta-D-erythrofuranosyl) nucleotide, 4′-thio nucleotide; carbocyclic nucleotide; 1,5-anhydrohexitol nucleotide; L-nucleotides; alpha-nucleotides; modified base nucleotide; phosphorodithioate linkage; threo-pentofuranosyl nucleotide; acyclic 3′,4′-seco nucleotide; acyclic 3,4-dihydroxybutyl nucleotide; acyclic 3,5-dihydroxypentyl nucleotide, 3′-3′-inverted nucleotide moiety; 3′-3′-inverted abasic moiety; 3′-2′-inverted nucleotide moiety; 3′-2′-inverted abasic moiety; 1,4-butanediol phosphate; 3′-phosphoramidate; hexylphosphate; aminohexyl phosphate; 3′-phosphate; 3′-phosphorothioate; phosphorodithioate; or bridging or non-bridging methylphosphonate moiety. Non-limiting examples of cap moieties are shown in FIG. 10.

Non-limiting examples of the 3′-cap include, but are not limited to, glyceryl, inverted deoxy abasic residue (moiety), 4′,5′-methylene nucleotide; 1-(beta-D-erythrofuranosyl) nucleotide; 4′-thio nucleotide, carbocyclic nucleotide; 5′-amino-alkyl phosphate; 1,3-diamino-2-propyl phosphate; 3-aminopropyl phosphate; 6-aminohexyl phosphate; 1,2-aminododecyl phosphate; hydroxypropyl phosphate; 1,5-anhydrohexitol nucleotide; L-nucleotide; alpha-nucleotide; modified base nucleotide; phosphorodithioate; threo-pentofuranosyl nucleotide; acyclic 3′,4′-seco nucleotide; 3,4-dihydroxybutyl nucleotide; 3,5-dihydroxypentyl nucleotide, 5′-5′-inverted nucleotide moiety; 5′-5′-inverted abasic moiety; 5′-phosphoramidate; 5′-phosphorothioate; 1,4-butanediol phosphate; 5′-amino; bridging and/or non-bridging 5′-phosphoramidate, phosphorothioate and/or phosphorodithioate, bridging or non bridging methylphosphonate and 5′-mercapto moieties (for more details see Beaucage and Iyer, 1993, Tetrahedron 49, 1925; incorporated by reference herein).

By the term “non-nucleotide” is meant any group or compound which can be incorporated into a nucleic acid chain in the place of one or more nucleotide units, including either sugar and/or phosphate substitutions, and allows the remaining bases to exhibit their enzymatic activity. The group or compound is abasic in that it does not contain a commonly recognized nucleotide base, such as adenosine, guanine, cytosine, uracil or thymine and therefore lacks a base at the 1′-position.

An “alkyl” group refers to a saturated aliphatic hydrocarbon, including straight-chain, branched-chain, and cyclic alkyl groups. Preferably, the alkyl group has 1 to 12 carbons. More preferably, it is a lower alkyl of from 1 to 7 carbons, more preferably 1 to 4 carbons. The alkyl group can be substituted or unsubstituted. When substituted the substituted group(s) is preferably, hydroxyl, cyano, alkoxy, ═O, ═S, NO₂ or N(CH3)₂, amino, or SH. The term also includes alkenyl groups that are unsaturated hydrocarbon groups containing at least one carbon-carbon double bond, including straight-chain, branched-chain, and cyclic groups. Preferably, the alkenyl group has 1 to 12 carbons. More preferably, it is a lower alkenyl of from 1 to 7 carbons, more preferably 1 to 4 carbons. The alkenyl group may be substituted or unsubstituted. When substituted the substituted group(s) is preferably, hydroxyl, cyano, alkoxy, ═O, ═S, NO₂, halogen, N(CH3)₂, amino, or SH. The term “alkyl” also includes alkynyl groups that have an unsaturated hydrocarbon group containing at least one carbon-carbon triple bond, including straight-chain, branched-chain, and cyclic groups. Preferably, the alkynyl group has 1 to 12 carbons. More preferably, it is a lower alkynyl of from 1 to 7 carbons, more preferably 1 to 4 carbons. The alkynyl group may be substituted or unsubstituted. When substituted the substituted group(s) is preferably, hydroxyl, cyano, alkoxy, ═O, ═S, NO2 or N(CH3)₂, amino or SH.

Such alkyl groups can also include aryl, alkylaryl, carbocyclic aryl, heterocyclic aryl, amide and ester groups. An “aryl” group refers to an aromatic group that has at least one ring having a conjugated pi electron system and includes carbocyclic aryl, heterocyclic aryl and biaryl groups, all of which may be optionally substituted. The preferred substituent(s) of aryl groups are halogen, trihalomethyl, hydroxyl, SH, OH, cyano, alkoxy, alkyl, alkenyl, alkynyl, and amino groups. An “alkylaryl” group refers to an alkyl group (as described above) covalently joined to an aryl group (as described above). Carbocyclic aryl groups are groups wherein the ring atoms on the aromatic ring are all carbon atoms. The carbon atoms are optionally substituted. Heterocyclic aryl groups are groups having from 1 to 3 heteroatoms as ring atoms in the aromatic ring and the remainder of the ring atoms are carbon atoms. Suitable heteroatoms include oxygen, sulfur, and nitrogen, and suitable heterocyclic groups include furanyl, thienyl, pyridyl, pyrrolyl, N-lower alkyl pyrrolo, pyrimidyl, pyrazinyl, imidazolyl and the like, all optionally substituted. An “amide” refers to an —C(O)—NH—R, where R is either alkyl, aryl, alkylaryl or hydrogen. An “ester” refers to an —C(O)—OR′, where R is either alkyl, aryl, alkylaryl or hydrogen.

“Nucleotide” as used herein, and as recognized in the art, includes natural bases (standard), and modified bases well known in the art. Such bases are generally located at the 1′ position of a nucleotide sugar moiety. Nucleotides generally comprise a base, sugar and a phosphate group. The nucleotides can be unmodified or modified at the sugar, phosphate and/or base moiety, (also referred to interchangeably as nucleotide analogs, modified nucleotides, non-natural nucleotides, non-standard nucleotides and other; see, for example, Usman and McSwiggen, supra; Eckstein et al., International PCT Publication No. WO 92/07065; Usman et al., International PCT Publication No. WO 93/15187; Uhlman & Peyman, supra, all are hereby incorporated by reference herein). There are several examples of modified nucleic acid bases known in the art as summarized by Limbach et al., 1994, Nucleic Acids Res. 22, 2183. Some of the non-limiting examples of base modifications that can be introduced into nucleic acid molecules include, inosine, purine, pyridin-4-one, pyridin-2-one, phenyl, pseudouracil, 2,4,6-trimethoxy benzene, 3-methyl uracil, dihydrouridine, naphthyl, aminophenyl, 5-alkylcytidines (e.g., 5-methylcytidine), 5-alkyluridines (e.g., ribothymidine), 5-halouridine (e.g., 5-bromouridine) or 6-azapyrimidines or 6-alkylpyrimidines (e.g. 6-methyluridine), propyne, and others (Burgin et al., 1996, Biochemistry, 35, 14090; Uhlman & Peyman, supra). By “modified bases” in this aspect is meant nucleotide bases other than adenine, guanine, cytosine and uracil at 1′ position or their equivalents.

In one embodiment, the invention features modified siNA molecules, with phosphate backbone modifications comprising one or more phosphorothioate, phosphorodithioate, methylphosphonate, phosphotriester, morpholino, amidate carbamate, carboxymethyl, acetamidate, polyamide, sulfonate, sulfonamide, sulfamate, formacetal, thioformacetal, and/or alkylsilyl, substitutions. For a review of oligonucleotide backbone modifications, see Hunziker and Leumann, 1995, Nucleic Acid Analogues: Synthesis and Properties, in Modern Synthetic Methods, VCH, 331-417, and Mesmaeker et al., 1994, Novel Backbone Replacements for Oligonucleotides, in Carbohydrate Modifications in Antisense Research, ACS, 24-39.

By “abasic” is meant sugar moieties lacking a base or having other chemical groups in place of a base at the 1′ position, see for example Adamic et al., U.S. Pat. No. 5,998,203.

By “unmodified nucleoside” is meant one of the bases adenine, cytosine, guanine, thymine, or uracil joined to the 1′ carbon of β-D-ribo-furanose.

By “modified nucleoside” is meant any nucleotide base which contains a modification in the chemical structure of an unmodified nucleotide base, sugar and/or phosphate. Non-limiting examples of modified nucleotides are shown by Formulae I-VII and/or other modifications described herein.

In connection with 2′-modified nucleotides as described for the present invention, by “amino” is meant 2′—NH₂ or 2′-O—NH₂, which can be modified or unmodified. Such modified groups are described, for example, in Eckstein et al., U.S. Pat. No. 5,672,695 and Matulic-Adamic et al., U.S. Pat. No. 6,248,878, which are both incorporated by reference in their entireties.

Various modifications to nucleic acid siNA structure can be made to enhance the utility of these molecules. Such modifications will enhance shelf-life, half-life in vitro, stability, and ease of introduction of such oligonucleotides to the target site, e.g., to enhance penetration of cellular membranes, and confer the ability to recognize and bind to targeted cells.

Administration of Nucleic Acid Molecules

An siNA molecule of the invention can be adapted for use to prevent or treat diabetes (type I and/or type II), atherosclerosis, cancer, obesity, and viral infection, and/or any other trait, disease, disorder or condition that is related to or will respond to the levels of SCD in a cell or tissue, alone or in combination with other therapies. For example, an siNA molecule can comprise a delivery vehicle, including liposomes, for administration to a subject, carriers and diluents and their salts, and/or can be present in pharmaceutically acceptable formulations. Methods for the delivery of nucleic acid molecules are described in Akhtar et al., 1992, Trends Cell Bio., 2, 139; Delivery Strategies for Antisense Oligonucleotide Therapeutics, ed. Akhtar, 1995, Maurer et al., 1999, Mol. Membr. Biol., 16, 129-140; Hofland and Huang, 1999, Handb. Exp. Pharmacol., 137, 165-192; and Lee et al., 2000, ACS Symp. Ser., 752, 184-192, all of which are incorporated herein by reference. Beigelman et al., U.S. Pat. No. 6,395,713 and Sullivan et al., PCT WO 94/02595 further describe the general methods for delivery of nucleic acid molecules. These protocols can be utilized for the delivery of virtually any nucleic acid molecule. Nucleic acid molecules can be administered to cells by a variety of methods known to those of skill in the art, including, but not restricted to, encapsulation in liposomes, by iontophoresis, or by incorporation into other vehicles, such as biodegradable polymers, hydrogels, cyclodextrins (see for example Gonzalez et al., 1999, Bioconjugate Chem., 10, 1068-1074; Wang et al., International PCT publication Nos. WO 03/47518 and WO 03/46185), poly(lactic-co-glycolic)acid (PLGA) and PLCA microspheres (see for example U.S. Pat. No. 6,447,796 and US Patent Application Publication No. US 2002130430), biodegradable nanocapsules, and bioadhesive microspheres, or by proteinaceous vectors (O'Hare and Normand, International PCT Publication No. WO 00/53722). In another embodiment, the nucleic acid molecules of the invention can also be formulated or complexed with polyethyleneimine and derivatives thereof, such as polyethyleneimine-polyethyleneglycol-N-acetylgalactosamine (PEI-PEG-GAL) or polyethyleneimine-polyethyleneglycol-tri-N-acetylgalactosamine (PEI-PEG-triGAL) derivatives. In one embodiment, the nucleic acid molecules of the invention are formulated as described in United States Patent Application Publication No. 20030077829, incorporated by reference herein in its entirety.

In one embodiment, an siNA molecule of the invention is complexed with membrane disruptive agents such as those described in U.S. Patent Application Publication No. 20010007666, incorporated by reference herein in its entirety including the drawings. In another embodiment, the membrane disruptive agent or agents and the siNA molecule are also complexed with a cationic lipid or helper lipid molecule, such as those lipids described in U.S. Pat. No. 6,235,310, incorporated by reference herein in its entirety including the drawings.

In one embodiment, an siNA molecule of the invention is complexed with delivery systems as described in U.S. Patent Application Publication No. 2003077829 and International PCT Publication Nos. WO 00/03683 and WO 02/087541, all incorporated by reference herein in their entirety including the drawings.

In one embodiment, the nucleic acid molecules of the invention are administered via pulmonary delivery, such as by inhalation of an aerosol or spray dried formulation administered by an inhalation device or nebulizer, providing rapid local uptake of the nucleic acid molecules into relevant pulmonary tissues. Solid particulate compositions containing respirable dry particles of micronized nucleic acid compositions can be prepared by grinding dried or lyophilized nucleic acid compositions, and then passing the micronized composition through, for example, a 400 mesh screen to break up or separate out large agglomerates. A solid particulate composition comprising the nucleic acid compositions of the invention can optionally contain a dispersant which serves to facilitate the formation of an aerosol as well as other therapeutic compounds. A suitable dispersant is lactose, which can be blended with the nucleic acid compound in any suitable ratio, such as a 1 to 1 ratio by weight.

Aerosols of liquid particles comprising a nucleic acid composition of the invention can be produced by any suitable means, such as with a nebulizer (see for example U.S. Pat. No. 4,501,729). Nebulizers are commercially available devices which transform solutions or suspensions of an active ingredient into a therapeutic aerosol mist either by means of acceleration of a compressed gas, typically air or oxygen, through a narrow venturi orifice or by means of ultrasonic agitation. Suitable formulations for use in nebulizers comprise the active ingredient in a liquid carrier in an amount of up to 40% w/w preferably less than 20% w/w of the formulation. The carrier is typically water or a dilute aqueous alcoholic solution, preferably made isotonic with body fluids by the addition of, for example, sodium chloride or other suitable salts. Optional additives include preservatives if the formulation is not prepared sterile, for example, methyl hydroxybenzoate, anti-oxidants, flavorings, volatile oils, buffering agents and emulsifiers and other formulation surfactants. The aerosols of solid particles comprising the active composition and surfactant can likewise be produced with any solid particulate aerosol generator. Aerosol generators for administering solid particulate therapeutics to a subject produce particles which are respirable, as explained above, and generate a volume of aerosol containing a predetermined metered dose of a therapeutic composition at a rate suitable for human administration. One illustrative type of solid particulate aerosol generator is an insufflator. Suitable formulations for administration by insufflation include finely comminuted powders which can be delivered by means of an insufflator. In the insufflator, the powder, e.g., a metered dose thereof effective to carry out the treatments described herein, is contained in capsules or cartridges, typically made of gelatin or plastic, which are either pierced or opened in situ and the powder delivered by air drawn through the device upon inhalation or by means of a manually-operated pump. The powder employed in the insufflator consists either solely of the active ingredient or of a powder blend comprising the active ingredient, a suitable powder diluent, such as lactose, and an optional surfactant. The active ingredient typically comprises from 0.1 to 100 w/w of the formulation. A second type of illustrative aerosol generator comprises a metered dose inhaler. Metered dose inhalers are pressurized aerosol dispensers, typically containing a suspension or solution formulation of the active ingredient in a liquefied propellant. During use these devices discharge the formulation through a valve adapted to deliver a metered volume to produce a fine particle spray containing the active ingredient. Suitable propellants include certain chlorofluorocarbon compounds, for example, dichlorodifluoromethane, trichlorofluoromethane, dichlorotetrafluoroethane and mixtures thereof. The formulation can additionally contain one or more co-solvents, for example, ethanol, emulsifiers and other formulation surfactants, such as oleic acid or sorbitan trioleate, anti-oxidants and suitable flavoring agents. Other methods for pulmonary delivery are described in, for example US Patent Application No. 20040037780, and U.S. Pat. Nos. 6,592,904; 6,582,728; 6,565,885.

In one embodiment, delivery systems of the invention include, for example, aqueous and nonaqueous gels, creams, multiple emulsions, microemulsions, liposomes, ointments, aqueous and nonaqueous solutions, lotions, aerosols, hydrocarbon bases and powders, and can contain excipients such as solubilizers, permeation enhancers (e.g., fatty acids, fatty acid esters, fatty alcohols and amino acids), and hydrophilic polymers (e.g., polycarbophil and polyvinylpyrolidone). In one embodiment, the pharmaceutically acceptable carrier is a liposome or a transdermal enhancer. Examples of liposomes which can be used in this invention include the following: (1) CellFectin, 1:1.5 (M/M) liposome formulation of the cationic lipid N,NI,NII,NIII-tetramethyl-N,NI,NII,NIII-tetrapalmit-y-spermine and dioleoyl phosphatidylethanolamine (DOPE) (GIBCO BRL); (2) Cytofectin GSV, 2:1 (M/M) liposome formulation of a cationic lipid and DOPE (Glen Research); (3) DOTAP (N-[1-(2,3-dioleoyloxy)-N,N,N-tri-methyl-ammoniummethylsulfate) (Boehringer Manheim); and (4) Lipofectamine, 3:1 (M/M) liposome formulation of the polycationic lipid DOSPA and the neutral lipid DOPE (GIBCO BRL).

In one embodiment, delivery systems of the invention include patches, tablets, suppositories, pessaries, gels and creams, and can contain excipients such as solubilizers and enhancers (e.g., propylene glycol, bile salts and amino acids), and other vehicles (e.g., polyethylene glycol, fatty acid esters and derivatives, and hydrophilic polymers such as hydroxypropylmethylcellulose and hyaluronic acid).

In one embodiment, siNA molecules of the invention are formulated or complexed with polyethylenimine (e.g., linear or branched PEI) and/or polyethylenimine derivatives, including for example grafted PEIs such as galactose PEI, cholesterol PEI, antibody derivatized PEI, and polyethylene glycol PEI (PEG-PEI) derivatives thereof (see for example Ogris et al., 2001, AAPA PhannSci, 3, 1-11; Furgeson et al., 2003, Bioconjugate Chem., 14, 840-847; Kunath et al., 2002, Pharmaceutical Research, 19, 810-817; Choi et al., 2001, Bull. Korean Chem. Soc., 22, 46-52; Bettinger et al., 1999, Bioconjugate Chem., 10, 558-561; Peterson et al., 2002, Bioconjugate Chem., 13, 845-854; Erbacher et al., 1999, Journal of Gene Medicine Preprint, 1, 1-18; Godbey et al., 1999., PNAS USA, 96, 5177-5181; Godbey et al., 1999, Journal of Controlled Release, 60, 149-160; Diebold et al., 1999, Journal of Biological Chemistry, 274, 19087-19094; Thomas and Klibanov, 2002, PNAS USA, 99, 14640-14645; and Sagara, U.S. Pat. No. 6,586,524, incorporated by reference herein.

In one embodiment, an siNA molecule of the invention comprises a bioconjugate, for example a nucleic acid conjugate as described in Vargeese et al., U.S. Ser. No. 10/427,160, filed Apr. 30, 2003; U.S. Pat. No. 6,528,631; U.S. Pat. No. 6,335,434; U.S. Pat. No. 6,235,886; U.S. Pat. No. 6,153,737; U.S. Pat. No. 5,214,136; U.S. Pat. No. 5,138,045, all incorporated by reference herein.

Thus, the invention features a pharmaceutical composition comprising one or more nucleic acid(s) of the invention in an acceptable carrier, such as a stabilizer, buffer, and the like. The polynucleotides of the invention can be administered (e.g., RNA, DNA or protein) and introduced to a subject by any standard means, with or without stabilizers, buffers, and the like, to form a pharmaceutical composition. When it is desired to use a liposome delivery mechanism, standard protocols for formation of liposomes can be followed. The compositions of the present invention can also be formulated and used as creams, gels, sprays, oils and other suitable compositions for topical, dermal, or transdermal administration as is known in the art.

The present invention also includes pharmaceutically acceptable formulations of the compounds described. These formulations include salts of the above compounds, e.g., acid addition salts, for example, salts of hydrochloric, hydrobromic, acetic acid, and benzene sulfonic acid.

A pharmacological composition or formulation refers to a composition or formulation in a form suitable for administration, e.g., systemic or local administration, into a cell or subject, including for example a human. Suitable forms, in part, depend upon the use or the route of entry, for example oral, transdermal, or by injection. Such forms should not prevent the composition or formulation from reaching a target cell (i.e., a cell to which the negatively charged nucleic acid is desirable for delivery). For example, pharmacological compositions injected into the blood stream should be soluble. Other factors are known in the art, and include considerations such as toxicity and forms that prevent the composition or formulation from exerting its effect.

In one embodiment, siNA molecules of the invention are administered to a subject by systemic administration in a pharmaceutically acceptable composition or formulation. By “systemic administration” is meant in vivo systemic absorption or accumulation of drugs in the blood stream followed by distribution throughout the entire body. Administration routes that lead to systemic absorption include, without limitation: intravenous, subcutaneous, intraperitoneal, inhalation, oral, intrapulmonary and intramuscular. Each of these administration routes exposes the siNA molecules of the invention to an accessible diseased tissue. The rate of entry of a drug into the circulation has been shown to be a function of molecular weight or size. The use of a liposome or other drug carrier comprising the compounds of the instant invention can potentially localize the drug, for example, in certain tissue types, such as the tissues of the reticular endothelial system (RES). A liposome formulation that can facilitate the association of drug with the surface of cells, such as, lymphocytes and macrophages is also useful. This approach can provide enhanced delivery of the drug to target cells by taking advantage of the specificity of macrophage and lymphocyte immune recognition of abnormal cells.

By “pharmaceutically acceptable formulation” or “pharmaceutically acceptable composition” is meant, a composition or formulation that allows for the effective distribution of the nucleic acid molecules of the instant invention in the physical location most suitable for their desired activity. Non-limiting examples of agents suitable for formulation with the nucleic acid molecules of the instant invention include: P-glycoprotein inhibitors (such as Pluronic P85),; biodegradable polymers, such as poly (DL-lactide-coglycolide) microspheres for sustained release delivery (Emerich, D F et al, 1999, Cell Transplant, 8, 47-58); and loaded nanoparticles, such as those made of polybutylcyanoacrylate. Other non-limiting examples of delivery strategies for the nucleic acid molecules of the instant invention include material described in Boado et al., 1998, J. Pharm. Sci., 87, 1308-1315; Tyler et al., 1999, FEBS Lett., 421, 280-284; Pardridge et al., 1995, PNAS USA., 92, 5592-5596; Boado, 1995, Adv. Drug Delivery Rev., 15, 73-107; Aldrian-Herrada et al., 1998, Nucleic Acids Res., 26, 49104916; and Tyler et al., 1999, PNAS USA., 96, 7053-7058.

The invention also features the use of the composition comprising surface-modified liposomes containing poly (ethylene glycol) lipids (PEG-modified, or long-circulating liposomes or stealth liposomes). These formulations offer a method for increasing the accumulation of drugs in target tissues. This class of drug carriers resists opsonization and elimination by the mononuclear phagocytic system (MPS or RES), thereby enabling longer blood circulation times and enhanced tissue exposure for the encapsulated drug (Lasic et al. Chem. Rev. 1995, 95, 2601-2627; Ishiwata et al., Chem. Pharm. Bull. 1995, 43, 1005-1011). Such liposomes have been shown to accumulate selectively in tumors, presumably by extravasation and capture in the neovascularized target tissues (Lasic et al., Science 1995, 267, 1275-1276; Oku et al., 1995, Biochim. Biophys. Acta, 1238, 86-90). The long-circulating liposomes enhance the pharmacokinetics and pharmacodynamics of DNA and RNA, particularly compared to conventional cationic liposomes which are known to accumulate in tissues of the MPS (Liu et al., J. Biol. Chem. 1995, 42, 24864-24870; Choi et al., International PCT Publication No. WO 96/10391; Ansell et al., International PCT Publication No. WO 96/10390; Holland et al., International PCT Publication No. WO 96/10392). Long-circulating liposomes are also likely to protect drugs from nuclease degradation to a greater extent compared to cationic liposomes, based on their ability to avoid accumulation in metabolically aggressive MPS tissues such as the liver and spleen.

The present invention also includes compositions prepared for storage or administration that include a pharmaceutically effective amount of the desired compounds in a pharmaceutically acceptable carrier or diluent. Acceptable carriers or diluents for therapeutic use are well known in the pharmaceutical art, and are described, for example, in Remington's Pharmaceutical Sciences, Mack Publishing Co. (A. R. Gennaro edit. 1985), hereby incorporated by reference herein. For example, preservatives, stabilizers, dyes and flavoring agents can be provided. These include sodium benzoate, sorbic acid and esters of p-hydroxybenzoic acid. In addition, antioxidants and suspending agents can be used.

A pharmaceutically effective dose is that dose required to prevent, inhibit the occurrence, or treat (alleviate a symptom to some extent, preferably all of the symptoms) of a disease state. The pharmaceutically effective dose depends on the type of disease, the composition used, the route of administration, the type of mammal being treated, the physical characteristics of the specific mammal under consideration, concurrent medication, and other factors that those skilled in the medical arts will recognize. Generally, an amount between 0.1 mg/kg and 100 mg/kg body weight/day of active ingredients is administered dependent upon potency of the negatively charged polymer.

The nucleic acid molecules of the invention and formulations thereof can be administered orally, topically, parenterally, by inhalation or spray, or rectally in dosage unit formulations containing conventional non-toxic pharmaceutically acceptable carriers, adjuvants and/or vehicles. The term parenteral as used herein includes percutaneous, subcutaneous, intravascular (e.g., intravenous), intramuscular, or intrathecal injection or infusion techniques and the like. In addition, there is provided a pharmaceutical formulation comprising a nucleic acid molecule of the invention and a pharmaceutically acceptable carrier. One or more nucleic acid molecules of the invention can be present in association with one or more non-toxic pharmaceutically acceptable carriers and/or diluents and/or adjuvants, and if desired other active ingredients. The pharmaceutical compositions containing nucleic acid molecules of the invention can be in a form suitable for oral use, for example, as tablets, troches, lozenges, aqueous or oily suspensions, dispersible powders or granules, emulsion, hard or soft capsules, or syrups or elixirs.

Compositions intended for oral use can be prepared according to any method known to the art for the manufacture of pharmaceutical compositions and such compositions can contain one or more such sweetening agents, flavoring agents, coloring agents or preservative agents in order to provide pharmaceutically elegant and palatable preparations. Tablets contain the active ingredient in admixture with non-toxic pharmaceutically acceptable excipients that are suitable for the manufacture of tablets. These excipients can be, for example, inert diluents; such as calcium carbonate, sodium carbonate, lactose, calcium phosphate or sodium phosphate; granulating and disintegrating agents, for example, corn starch, or alginic acid; binding agents, for example starch, gelatin or acacia; and lubricating agents, for example magnesium stearate, stearic acid or talc. The tablets can be uncoated or they can be coated by known techniques. In some cases such coatings can be prepared by known techniques to delay disintegration and absorption in the gastrointestinal tract and thereby provide a sustained action over a longer period. For example, a time delay material such as glyceryl monosterate or glyceryl distearate can be employed.

Formulations for oral use can also be presented as hard gelatin capsules wherein the active ingredient is mixed with an inert solid diluent, for example, calcium carbonate, calcium phosphate or kaolin, or as soft gelatin capsules wherein the active ingredient is mixed with water or an oil medium, for example peanut oil, liquid paraffin or olive oil.

Aqueous suspensions contain the active materials in a mixture with excipients suitable for the manufacture of aqueous suspensions. Such excipients are suspending agents, for example sodium carboxymethylcellulose, methylcellulose, hydropropyl-methylcellulose, sodium alginate, polyvinylpyrrolidone, gum tragacanth and gum acacia; dispersing or wetting agents can be a naturally-occurring phosphatide, for example, lecithin, or condensation products of an alkylene oxide with fatty acids, for example polyoxyethylene stearate, or condensation products of ethylene oxide with long chain aliphatic alcohols, for example heptadecaethyleneoxycetanol, or condensation products of ethylene oxide with partial esters derived from fatty acids and a hexitol such as polyoxyethylene sorbitol monooleate, or condensation products of ethylene oxide with partial esters derived from fatty acids and hexitol anhydrides, for example polyethylene sorbitan monooleate. The aqueous suspensions can also contain one or more preservatives, for example ethyl, or n-propyl p-hydroxybenzoate, one or more coloring agents, one or more flavoring agents, and one or more sweetening agents, such as sucrose or saccharin.

Oily suspensions can be formulated by suspending the active ingredients in a vegetable oil, for example arachis oil, olive oil, sesame oil or coconut oil, or in a mineral oil such as liquid paraffin. The oily suspensions can contain a thickening agent, for example beeswax, hard paraffin or cetyl alcohol. Sweetening agents and flavoring agents can be added to provide palatable oral preparations. These compositions can be preserved by the addition of an anti-oxidant such as ascorbic acid

Dispersible powders and granules suitable for preparation of an aqueous suspension by the addition of water provide the active ingredient in admixture with a dispersing or wetting agent, suspending agent and one or more preservatives. Suitable dispersing or wetting agents or suspending agents are exemplified by those already mentioned above. Additional excipients, for example sweetening, flavoring and coloring agents, can also be present.

Pharmaceutical compositions of the invention can also be in the form of oil-in-water emulsions. The oily phase can be a vegetable oil or a mineral oil or mixtures of these. Suitable emulsifying agents can be naturally-occurring gums, for example gum acacia or gum tragacanth, naturally-occurring phosphatides, for example soy bean, lecithin, and esters or partial esters derived from fatty acids and hexitol, anhydrides, for example sorbitan monooleate, and condensation products of the said partial esters with ethylene oxide, for example polyoxyethylene sorbitan monooleate. The emulsions can also contain sweetening and flavoring agents.

Syrups and elixirs can be formulated with sweetening agents, for example glycerol, propylene glycol, sorbitol, glucose or sucrose. Such formulations can also contain a demulcent, a preservative and flavoring and coloring agents. The pharmaceutical compositions can be in the form of a sterile injectable aqueous or oleaginous suspension. This suspension can be formulated according to the known art using those suitable dispersing or wetting agents and suspending agents that have been mentioned above. The sterile injectable preparation can also be a sterile injectable solution or suspension in a non-toxic parentally acceptable diluent or solvent, for example as a solution in 1,3-butanediol. Among the acceptable vehicles and solvents that can be employed are water, Ringer's solution and isotonic sodium chloride solution. In addition, sterile, fixed oils are conventionally employed as a solvent or suspending medium. For this purpose, any bland fixed oil can be employed including synthetic mono- or diglycerides. In addition, fatty acids such as oleic acid find use in the preparation of injectables.

The nucleic acid molecules of the invention can also be administered in the form of suppositories, e.g., for rectal administration of the drug. These compositions can be prepared by mixing the drug with a suitable non-irritating excipient that is solid at ordinary temperatures but liquid at the rectal temperature and will therefore melt in the rectum to release the drug. Such materials include cocoa butter and polyethylene glycols.

Nucleic acid molecules of the invention can be administered parenterally in a sterile medium. The drug, depending on the vehicle and concentration used, can either be suspended or dissolved in the vehicle. Advantageously, adjuvants such as local anesthetics, preservatives and buffering agents can be dissolved in the vehicle.

Dosage levels of the order of from about 0.1 mg to about 140 mg per kilogram of body weight per day are useful in the treatment of the above-indicated conditions (about 0.5 mg to about 7 g per subject per day). The amount of active ingredient that can be combined with the carrier materials to produce a single dosage form varies depending upon the host treated and the particular mode of administration. Dosage unit forms generally contain between from about 1 mg to about 500 mg of an active ingredient.

It is understood that the specific dose level for any particular subject depends upon a variety of factors including the activity of the specific compound employed, the age, body weight, general health, sex, diet, time of administration, route of administration, and rate of excretion, drug combination and the severity of the particular disease undergoing therapy.

For administration to non-human animals, the composition can also be added to the animal feed or drinking water. It can be convenient to formulate the animal feed and drinking water compositions so that the animal takes in a therapeutically appropriate quantity of the composition along with its diet. It can also be convenient to present the composition as a premix for addition to the feed or drinking water.

The nucleic acid molecules of the present invention can also be administered to a subject in combination with other therapeutic compounds to increase the overall therapeutic effect. The use of multiple compounds to treat an indication can increase the beneficial effects while reducing the presence of side effects.

In one embodiment, the invention comprises compositions suitable for administering nucleic acid molecules of the invention to specific cell types. For example, the asialoglycoprotein receptor (ASGPr) (Wu and Wu, 1987, J. Biol. Chem. 262, 44294432) is unique to hepatocytes and binds branched galactose-terminal glycoproteins, such as asialoorosomucoid (ASOR). In another example, the folate receptor is overexpressed in many cancer cells. Binding of such glycoproteins, synthetic glycoconjugates, or folates to the receptor takes place with an affinity that strongly depends on the degree of branching of the oligosaccharide chain, for example, triatennary structures are bound with greater affinity than biatennary or monoatennary chains (Baenziger and Fiete, 1980, Cell, 22, 611-620; Connolly et al., 1982, J. Biol. Chem., 257, 939-945). Lee and Lee, 1987, Glycoconjugate J., 4, 317-328, obtained this high specificity through the use of N-acetyl-D-galactosamine as the carbohydrate moiety, which has higher affinity for the receptor, compared to galactose. This “clustering effect” has also been described for the binding and uptake of mannosyl-terminating glycoproteins or glycoconjugates (Ponpipom et al., 1981, J. Med. Chem., 24, 1388-1395). The use of galactose, galactosamine, or folate based conjugates to transport exogenous compounds across cell membranes can provide a targeted delivery approach to, for example, the treatment of liver disease, cancers of the liver, or other cancers. The use of bioconjugates can also provide a reduction in the required dose of therapeutic compounds required for treatment. Furthermore, therapeutic bioavailability, pharmacodynamics, and pharmacokinetic parameters can be modulated through the use of nucleic acid bioconjugates of the invention. Non-limiting examples of such bioconjugates are described in Vargeese et al., U.S. Ser. No. 10/201,394, filed Aug. 13, 2001; and Matulic-Adamic et al., U.S. Ser. No. 60/362,016, filed Mar. 6, 2002.

Alternatively, certain siNA molecules of the instant invention can be expressed within cells from eukaryotic promoters (e.g., Izant and Weintraub, 1985, Science, 229, 345; McGarry and Lindquist, 1986, Proc. Natl. Acad. Sci., USA 83, 399; Scanlon et al., 1991, Proc. Natl. Acad. Sci. USA, 88, 10591-5; Kashani-Sabet et al., 1992, Antisense Res. Dev., 2, 3-15; Dropulic et al., 1992, J. Virol., 66, 1432-41; Weerasinghe et al., 1991, J. Virol., 65, 5531-4; Ojwang et al., 1992, Proc. Natl. Acad. Sci. USA, 89, 10802-6; Chen et al., 1992, Nucleic Acids Res., 20, 4581-9; Sarver et al., 1990 Science, 247, 1222-1225; Thompson et al., 1995, Nucleic Acids Res., 23, 2259; Good et al., 1997, Gene Therapy, 4, 45. Those skilled in the art realize that any nucleic acid can be expressed in eukaryotic cells from the appropriate DNA/RNA vector. The activity of such nucleic acids can be augmented by their release from the primary transcript by a enzymatic nucleic acid (Draper et al., PCT WO 93/23569, and Sullivan et al., PCT WO 94/02595; Ohkawa et al., 1992, Nucleic Acids Symp. Ser., 27, 15-6; Taira et al., 1991, Nucleic Acids Res., 19, 5125-30; Ventura et al., 1993, Nucleic Acids Res., 21, 3249-55; Chowrira et al., 1994, J. Biol. Chem., 269, 25856.

In another aspect of the invention, RNA molecules of the present invention can be expressed from transcription units (see for example Couture et al., 1996, TIG., 12, 510) inserted into DNA or RNA vectors. The recombinant vectors can be DNA plasmids or viral vectors. siNA expressing viral vectors can be constructed based on, but not limited to, adeno-associated virus, retrovirus, adenovirus, or alphavirus. In another embodiment, pol III based constructs are used to express nucleic acid molecules of the invention (see for example Thompson, U.S. Pats. Nos. 5,902,880 and 6,146,886). The recombinant vectors capable of expressing the siNA molecules can be delivered as described above, and persist in target cells. Alternatively, viral vectors can be used that provide for transient expression of nucleic acid molecules. Such vectors can be repeatedly administered as necessary. Once expressed, the siNA molecule interacts with the target mRNA and generates an RNAi response. Delivery of siNA molecule expressing vectors can be systemic, such as by intravenous or intramuscular administration, by administration to target cells ex-planted from a subject followed by reintroduction into the subject, or by any other means that would allow for introduction into the desired target cell (for a review see Couture et al., 1996, TIG., 12, 510).

In one aspect the invention features an expression vector comprising a nucleic acid sequence encoding at least one siNA molecule of the instant invention. The expression vector can encode one or both strands of an siNA duplex, or a single self-complementary strand that self hybridizes into an siNA duplex. The nucleic acid sequences encoding the siNA molecules of the instant invention can be operably linked in a manner that allows expression of the siNA molecule (see for example Paul et al., 2002, Nature Biotechnology, 19, 505; Miyagishi and Taira, 2002, Nature Biotechnology, 19, 497; Lee et al., 2002, Nature Biotechnology, 19, 500; and Novina et al., 2002, Nature Medicine, advance online publication doi: 10.1038/nm725).

In another aspect, the invention features an expression vector comprising: a) a transcription initiation region (e.g., eukaryotic pol I, II or III initiation region); b) a transcription termination region (e.g., eukaryotic pol I, II or III termination region); and c) a nucleic acid sequence encoding at least one of the siNA molecules of the instant invention, wherein said sequence is operably linked to said initiation region and said termination region in a manner that allows expression and/or delivery of the siNA molecule. The vector can optionally include an open reading frame (ORF) for a protein operably linked on the 5′ side or the 3′-side of the sequence encoding the siNA of the invention; and/or an intron (intervening sequences).

Transcription of the siNA molecule sequences can be driven from a promoter for eukaryotic RNA polymerase I (pol I), RNA polymerase II (pol II), or RNA polymerase III (pol III). Transcripts from pol 11 or pol III promoters are expressed at high levels in all cells; the levels of a given pol 11 promoter in a given cell type depends on the nature of the gene regulatory sequences (enhancers, silencers, etc.) present nearby. Prokaryotic RNA polymerase promoters are also used, providing that the prokaryotic RNA polymerase enzyme is expressed in the appropriate cells (Elroy-Stein and Moss, 1990, Proc. Natl. Acad. Sci. U S A, 87, 6743-7; Gao and Huang 1993, Nucleic Acids Res., 21, 2867-72; Lieber et al., 1993, Methods Enzymol., 217, 47-66; Zhou et al., 1990, Mol. Cell. Biol., 10, 4529-37). Several investigators have demonstrated that nucleic acid molecules expressed from such promoters can function in mammalian cells (e.g. Kashani-Sabet et al., 1992, Antisense Res. Dev., 2, 3-15; Ojwang et al., 1992, Proc. Natl. Acad. Sci. USA, 89, 10802-6; Chen et al., 1992, Nucleic Acids Res., 20, 4581-9; Yu et al., 1993, Proc. Natl. Acad. Sci. USA, 90, 6340-4; L'Huillier et al., 1992, EMBO J., 11, 4411-8; Lisziewicz et al., 1993, Proc. Natl. Acad. Sci. U.S. A, 90, 8000-4; Thompson et al., 1995, Nucleic Acids Res., 23, 2259; Sullenger & Cech, 1993, Science, 262, 1566). More specifically, transcription units such as the ones derived from genes encoding U6 small nuclear (snRNA), transfer RNA (tRNA) and adenovirus VA RNA are useful in generating high concentrations of desired RNA molecules such as siNA in cells (Thompson et al., supra; Couture and Stinchcomb, 1996, supra; Noonberg et al., 1994, Nucleic Acid Res., 22, 2830; Noonberg et al., U.S. Pat. No. 5,624,803; Good et al., 1997, Gene Ther., 4, 45; Beigelman et al., International PCT Publication No. WO 96/18736. The above siNA transcription units can be incorporated into a variety of vectors for introduction into mammalian cells, including but not restricted to, plasmid DNA vectors, viral DNA vectors (such as adenovirus or adeno-associated virus vectors), or viral RNA vectors (such as retroviral or alphavirus vectors) (for a review see Couture and Stinchcomb, 1996, supra).

In another aspect the invention features an expression vector comprising a nucleic acid sequence encoding at least one of the siNA molecules of the invention in a manner that allows expression of that siNA molecule. The expression vector comprises in one embodiment; a) a transcription initiation region; b) a transcription termination region; and c) a nucleic acid sequence encoding at least one strand of the siNA molecule, wherein the sequence is operably linked to the initiation region and the termination region in a manner that allows expression and/or delivery of the siNA molecule.

In another embodiment the expression vector comprises: a) a transcription initiation region; b) a transcription termination region; c) an open reading frame; and d) a nucleic acid sequence encoding at least one strand of an siNA molecule, wherein the sequence is operably linked to the 3′-end of the open reading frame and wherein the sequence is operably linked to the initiation region, the open reading frame and the termination region in a manner that allows expression and/or delivery of the siNA molecule. In yet another embodiment, the expression vector comprises: a) a transcription initiation region; b) a transcription termination region; c) an intron; and d) a nucleic acid sequence encoding at least one siNA molecule, wherein the sequence is operably linked to the initiation region, the intron and the termination region in a manner which allows expression and/or delivery of the nucleic acid molecule.

In another embodiment, the expression vector comprises: a) a transcription initiation region; b) a transcription termination region; c) an intron; d) an open reading frame; and e) a nucleic acid sequence encoding at least one strand of an siNA molecule, wherein the sequence is operably linked to the 3′-end of the open reading frame and wherein the sequence is operably linked to the initiation region, the intron, the open reading frame and the termination region in a manner which allows expression and/or delivery of the siNA molecule.

SCD Biology and Biochemistry

Stearoyl-CoA desaturase (SCD) is the rate-limiting enzyme in the biosynthesis of monounsaturated fatty acids, including oleate (C18:1) and palmitoleate (C16:1). SCD catalyzes the introduction of the cis double bond in the delta-9 position of fatty acyl-CoA substrates, such as palmitoyl-CoA and stearoyl-CoA, which are converted to palmitoleoyl-CoA (16:1) and oleoyl-CoA (18:1), respectively. These fatty acids are essential components of membrane phospholipids, triglycerides, cholesterol esters, and wax esters. Modulation of phospholipid composition ultimately determines physical properties, such as membrane fluidity. Further, effects on the composition of cholesterol esters and triglycerides can substantially affect lipoprotein metabolism and adiposity. SCD expression is sensitive to dietary factors, including polyunsaturated fatty acids, cholesterol and vitamin A, hormonal changes (i.e., insulin, leptin, and glucagon), developmental processes, temperature changes, thiazolinediones, metals, alcohol, peroxisomal proliferators, and certain phenolic compounds. High SCD activity has been implicated in a wide range of diseases and disorders including diabetes, atherosclerosis, cancer, obesity, and viral infection (Ntambi et al., 2002, PNAS USA, 99, 11482-11486).

Several SCD isoforms (SCD1-3) have been identified in the mouse. Mice having defective SCD expression provide useful information in determining the relevance of SCD in models of obesity, diabetes, and insulin resistance. For example, new insights into the physiological role of the SCD1 gene and its endogenous products have been reported from recent studies of the asebia mouse strains (ab^(j) and ab^(2j)) that have naturally occurring mutations in SCD1 (Zheng et al, 1999, Nature Genetics, 23, 268-270), as well as a laboratory mouse model with a targeted disruption (SCD1 −/−) (Miyazaki et al., 2001, J. Biol. Chem., 276, 39455-39461). Mice having a targeted disruption of the SCD1 isoform have reduced body adiposity, increased insulin sensitivity, and are resistant to diet-induced weight gain. The protection from obesity in these mice involves increased energy expenditure and increased oxygen consumption. Compared with the wild-type mice, SCD1 −/− mice have increased levels of plasma ketone bodies, but also have reduced levels of plasma insulin and leptin. The expression of several genes controlling lipid oxidation are up-regulated in SCD1−/− mice, whereas lipid synthesis genes are down-regulated in SCD1−/− mice. These observations suggest that a consequence of SCD1 deficiency is an activation of lipid oxidation in addition to reduced triglyceride synthesis and storage. Aside from the dramatic alterations in triglyceride and cholesterol metabolism, the SCD1−/− mice are considerably leaner than their wild-type counterparts. (Ntambi et al., 2002, PNAS USA, 99, 11482-11486).

The use of small interfering nucleic acid molecules targeting SCD, therefore provides a class of novel therapeutic agents that can be used in the treatment, alleviation, or prevention of diabetes (type I and/or type II), atherosclerosis, cancer, obesity, and viral infection, alone or in combination with other therapies.

EXAMPLES

The following are non-limiting examples showing the selection, isolation, synthesis and activity of nucleic acids of the instant invention.

Example 1 Tandem Synthesis of siNA Constructs

Exemplary siNA molecules of the invention are synthesized in tandem using a cleavable linker, for example, a succinyl-based linker. Tandem synthesis as described herein is followed by a one-step purification process that provides RNAi molecules in high yield. This approach is highly amenable to siNA synthesis in support of high throughput RNAi screening, and can be readily adapted to multi-column or multi-well synthesis platforms.

After completing a tandem synthesis of an siNA oligo and its complement in which the 5′-terminal dimethoxytrityl (5′-O-DMT) group remains intact (trityl on synthesis), the oligonucleotides are deprotected as described above. Following deprotection, the siNA sequence strands are allowed to spontaneously hybridize. This hybridization yields a duplex in which one strand has retained the 5′-O-DMT group while the complementary strand comprises a terminal 5′-hydroxyl. The newly formed duplex behaves as a single molecule during routine solid-phase extraction purification (Trityl-On purification) even though only one molecule has a dimethoxytrityl group. Because the strands form a stable duplex, this dimethoxytrityl group (or an equivalent group, such as other trityl groups or other hydrophobic moieties) is all that is required to purify the pair of oligos, for example, by using a C18 cartridge.

Standard phosphoramidite synthesis chemistry is used up to the point of introducing a tandem linker, such as an inverted deoxy abasic succinate or glyceryl succinate linker (see FIG. 1) or an equivalent cleavable linker. A non-limiting example of linker coupling conditions that can be used includes a hindered base such as diisopropylethylamine (DIPA) and/or DMAP in the presence of an activator reagent such as Bromotripyrrolidinophosphoniumhexafluororophosphate (PyBrOP). After the linker is coupled, standard synthesis chemistry is utilized to complete synthesis of the second sequence leaving the terminal the 5′-O-DMT intact. Following synthesis, the resulting oligonucleotide is deprotected according to the procedures described herein and quenched with a suitable buffer, for example with 50 mM NaOAc or 1.5M NH₄H₂CO₃.

Purification of the siNA duplex can be readily accomplished using solid phase extraction, for example, using a Waters C18 SepPak 1 g cartridge conditioned with 1 column volume (CV) of acetonitrile, 2 CV H₂O, and 2 CV 50 mM NaOAc. The sample is loaded and then washed with 1 CV H2O or 50 mM NaOAc. Failure sequences are eluted with 1 CV 14% ACN (Aqueous with 50 mM NaOAc and 50 mM NaCl). The column is then washed, for example with 1 CV H2O followed by on-column detritylation, for example by passing 1 CV of 1% aqueous trifluoroacetic acid (TFA) over the column, then adding a second CV of 1% aqueous TFA to the column and allowing to stand for approximately 10 minutes. The remaining TFA solution is removed and the column washed with H2O followed by I CV 1 M NaCl and additional H2O. The siNA duplex product is then eluted, for example, using 1 CV 20% aqueous CAN.

FIG. 2 provides an example of MALDI-TOF mass spectrometry analysis of a purified siNA construct in which each peak corresponds to the calculated mass of an individual siNA strand of the siNA duplex. The same purified siNA provides three peaks when analyzed by capillary gel electrophoresis (CGE), one peak presumably corresponding to the duplex siNA, and two peaks presumably corresponding to the separate siNA sequence strands. Ion exchange HPLC analysis of the same siNA contract only shows a single peak. Testing of the purified siNA construct using a luciferase reporter assay described below demonstrated the same RNAi activity compared to siNA constructs generated from separately synthesized oligonucleotide sequence strands.

Example 2 Identification of Potential siNA Target Sites in Any RNA Sequence

The sequence of an RNA target of interest, such as a viral or human mRNA transcript, is screened for target sites, for example by using a computer folding algorithm. In a non-limiting example, the sequence of a gene or RNA gene transcript derived from a database, such as Genbank, is used to generate siNA targets having complementarity to the target. Such sequences can be obtained from a database, or can be determined experimentally as known in the art. Target sites that are known, for example, those target sites determined to be effective target sites based on studies with other nucleic acid molecules, for example ribozymes or antisense, or those targets known to be associated with a disease or condition such as those sites containing mutations or deletions, can be used to design siNA molecules targeting those sites. Various parameters can be used to determine which sites are the most suitable target sites within the target RNA sequence. These parameters include but are not limited to secondary or tertiary RNA structure, the nucleotide base composition of the target sequence, the degree of homology between various regions of the target sequence, or the relative position of the target sequence within the RNA transcript. Based on these determinations, any number of target sites within the RNA transcript can be chosen to screen siNA molecules for efficacy, for example by using in vitro RNA cleavage assays, cell culture, or animal models. In a non-limiting example, anywhere from 1 to 1000 target sites are chosen within the transcript based on the size of the siNA construct to be used. High throughput screening assays can be developed for screening siNA molecules using methods known in the art, such as with multi-well or multi-plate assays to determine efficient reduction in target gene expression.

Example 3 Selection of siNA Molecule Target Sites in an RNA

The following non-limiting steps can be used to carry out the selection of siNAs targeting a given gene sequence or transcript.

1. The target sequence is parsed in silico into a list of all fragments or subsequences of a particular length, for example 23 nucleotide fragments, contained within the target sequence. This step is typically carried out using a custom Perl script, but commercial sequence analysis programs such as Oligo, MacVector, or the GCG Wisconsin Package can be employed as well.

2. In some instances the siNAs correspond to more than one target sequence; such would be the case for example in targeting different transcripts of the same gene, targeting different transcripts of more than one gene, or for targeting both the human gene and an animal homolog. In this case, a subsequence list of a particular length is generated for each of the targets, and then the lists are compared to find matching sequences in each list. The subsequences are then ranked according to the number of target sequences that contain the given subsequence; the goal is to find subsequences that are present in most or all of the target sequences. Alternately, the ranking can identify subsequences that are unique to a target sequence, such as a mutant target sequence. Such an approach would enable the use of siNA to target specifically the mutant sequence and not effect the expression of the normal sequence.

3. In some instances the siNA subsequences are absent in one or more sequences while present in the desired target sequence; such would be the case if the siNA targets a gene with a paralogous family member that is to remain untargeted. As in case 2 above, a subsequence list of a particular length is generated for each of the targets, and then the lists are compared to find sequences that are present in the target gene but are absent in the untargeted paralog.

4. The ranked siNA subsequences can be further analyzed and ranked according to GC content. A preference can be given to sites containing 30-70% GC, with a further preference to sites containing 40-60% GC.

5. The ranked siNA subsequences can be further analyzed and ranked according to self-folding and internal hairpins. Weaker internal folds are preferred; strong hairpin structures are to be avoided.

6: The ranked siNA subsequences can be further analyzed and ranked according to whether they have runs of GGG or CCC in the sequence. GGG (or even more Gs) in either strand can make oligonucleotide synthesis problematic and can potentially interfere with RNAi activity, so it is avoided whenever better sequences are available. CCC is searched in the target strand because that will place GGG in the antisense strand.

7. The ranked siNA subsequences can be further analyzed and ranked according to whether they have the dinucleotide UU (uridine dinucleotide) on the 3′-end of the sequence, and/or AA on the 5′-end of the sequence (to yield 3′ UU on the antisense sequence). These sequences allow one to design siNA molecules with terminal TT thymidine dinucleotides.

8. Four or five target sites are chosen from the ranked list of subsequences as described above. For example, in subsequences having 23 nucleotides, the right 21 nucleotides of each chosen 23-mer subsequence are then designed and synthesized for the upper (sense) strand of the siNA duplex, while the reverse complement of the left 21 nucleotides of each chosen 23-mer subsequence are then designed and synthesized for the lower (antisense) strand of the siNA duplex (see Tables II and III). If terminal TT residues are desired for the sequence (as described in paragraph 7), then the two 3′ terminal nucleotides of both the sense and antisense strands are replaced by TT prior to synthesizing the oligos.

9. The siNA molecules are screened in an in vitro, cell culture or animal model system to identify the most active siNA molecule or the most preferred target site within the target RNA sequence.

10. Other design considerations can be used when selecting target nucleic acid sequences, see, for example, Reynolds et al., 2004, Nature Biotechnology Advanced Online Publication, 1 Feb. 2004, doi:10.1038/nbt936 and Ui-Tei et al., 2004, Nucleic Acids Research, 32, doi:10.1093/nar/gkh247.

In an alternate approach, a pool of siNA constructs specific to a SCD target sequence is used to screen for target sites in cells expressing SCD RNA, such as such HepG2, MDA-MB-231 or A549 cells. The general strategy used in this approach is shown in FIG. 9. A non-limiting example of such is a pool comprising sequences having any of SEQ ID NOS 1-806. Cells expressing SCD are transfected with the pool of siNA constructs and cells that demonstrate a phenotype associated with SCD inhibition are sorted. The pool of siNA constructs can be expressed from transcription cassettes inserted into appropriate vectors (see for example FIG. 7 and FIG. 8). The siNA from cells demonstrating a positive phenotypic change (e.g., decreased proliferation, decreased SCD mRNA levels or decreased SCD protein expression), are sequenced to determine the most suitable target site(s) within the target SCD RNA sequence.

Example 4 SCD Targeted siNA Design

siNA target sites were chosen by analyzing sequences of the SCD RNA target and optionally prioritizing the target sites on the basis of folding (structure of any given sequence analyzed to determine siNA accessibility to the target), by using a library of siNA molecules as described in Example 3, or alternately by using an in vitro siNA system as described in Example 6 herein. siNA molecules were designed that could bind each target and are optionally individually analyzed by computer folding to assess whether the siNA molecule can interact with the target sequence. Varying the length of the siNA molecules can be chosen to optimize activity. Generally, a sufficient number of complementary nucleotide bases are chosen to bind to, or otherwise interact with, the target RNA, but the degree of complementarity can be modulated to accommodate siNA duplexes or varying length or base composition. By using such methodologies, siNA molecules can be designed to target sites within any known RNA sequence, for example those RNA sequences corresponding to the any gene transcript.

Chemically modified siNA constructs are designed to provide nuclease stability for systemic administration in vivo and/or improved pharmacokinetic, localization, and delivery properties while preserving the ability to mediate RNAi activity. Chemical modifications as described herein are introduced synthetically using synthetic methods described herein and those generally known in the art. The synthetic siNA constructs are then assayed for nuclease stability in serum and/or cellular/tissue extracts (e.g. liver extracts). The synthetic siNA constructs are also tested in parallel for RNAi activity using an appropriate assay, such as a luciferase reporter assay as described herein or another suitable assay that can quantity RNAi activity. Synthetic siNA constructs that possess both nuclease stability and RNAi activity can be further modified and re-evaluated in stability and activity assays. The chemical modifications of the stabilized active siNA constructs can then be applied to any siNA sequence targeting any chosen RNA and used, for example, in target screening assays to pick lead siNA compounds for therapeutic development (see for example FIG. 11).

Example 5 Chemical Synthesis and Purification of siNA

siNA molecules can be designed to interact with various sites in the RNA message, for example, target sequences within the RNA sequences described herein. The sequence of one strand of the siNA molecule(s) is complementary to the target site sequences described above. The siNA molecules can be chemically synthesized using methods described herein. Inactive siNA molecules that are used as control sequences can be synthesized by scrambling the sequence of the siNA molecules such that it is not complementary to the target sequence. Generally, siNA constructs can by synthesized using solid phase oligonucleotide synthesis methods as described herein (see for example Usman et al., U.S. Pat. Nos. 5,804,683; 5,831,071; 5,998,203; 6,117,657; 6,353,098; 6,362,323; 6,437,117; 6,469,158; Scaringe et al., U.S. Pat. Nos. 6,111,086; 6,008,400; 6,111,086 all incorporated by reference herein in their entirety).

In a non-limiting example, RNA oligonucleotides are synthesized in a stepwise fashion using the phosphoramidite chemistry as is known in the art. Standard phosphoramidite chemistry involves the use of nucleosides comprising any of 5′-O-dimethoxytrityl, 2′-O-tert-butyldimethylsilyl, 3′-O-2-Cyanoethyl N,N-diisopropylphos-phoroamidite groups, and exocyclic amine protecting groups (e.g. N6-benzoyl adenosine, N4 acetyl cytidine, and N2-isobutyryl guanosine). Alternately, 2′-O—Silyl Ethers can be used in conjunction with acid-labile 2′-O-orthoester protecting groups in the synthesis of RNA as described by Scaringe supra. Differing 2′ chemistries can require different protecting groups, for example 2′-deoxy-2′-amino nucleosides can utilize N-phthaloyl protection as described by Usman et al., U.S. Pat. No. 5,631,360, incorporated by reference herein in its entirety).

During solid phase synthesis, each nucleotide is added sequentially (3′- to 5′-direction) to the solid support-bound oligonucleotide. The first nucleoside at the 3′-end of the chain is covalently attached to a solid support (e.g., controlled pore glass or polystyrene) using various linkers. The nucleotide precursor, a ribonucleoside phosphoramidite, and activator are combined resulting in the coupling of the second nucleoside phosphoramidite onto the 5′-end of the first nucleoside. The support is then washed and any unreacted 5′-hydroxyl groups are capped with a capping reagent such as acetic anhydride to yield inactive 5′-acetyl moieties. The trivalent phosphorus linkage is then oxidized to a more stable phosphate linkage. At the end of the nucleotide addition cycle, the 5′-O-protecting group is cleaved under suitable conditions (e.g., acidic conditions for trityl-based groups and Fluoride for silyl-based groups). The cycle is repeated for each subsequent nucleotide.

Modification of synthesis conditions can be used to optimize coupling efficiency, for example by using differing coupling times, differing reagent/phosphoramidite concentrations, differing contact times, differing solid supports and solid support linker chemistries depending on the particular chemical composition of the siNA to be synthesized. Deprotection and purification of the siNA can be performed as is generally described in Usman et al., U.S. Pat. No. 5,831,071, U.S. Pat. No. 6,353,098, U.S. Pat. No. 6,437,117, and Bellon et al., U.S. Pat. No. 6,054,576, U.S. Pat. No. 6,162,909, U.S. Pat. No. 6,303,773, or Scaringe supra, incorporated by reference herein in their entireties. Additionally, deprotection conditions can be modified to provide the best possible yield and purity of siNA constructs. For example, applicant has observed that oligonucleotides comprising 2′-deoxy-2′-fluoro nucleotides can degrade under inappropriate deprotection conditions. Such oligonucleotides are deprotected using aqueous methylamine at about 35° C. for 30 minutes. If the 2′-deoxy-2′-fluoro containing oligonucleotide also comprises ribonucleotides, after deprotection with aqueous methylamine at about 35° C. for 30 minutes, TEA-HF is added and the reaction maintained at about 65° C. for an additional 15 minutes.

Example 6 RNAi in Vitro Assay to Assess siNA Activity

An in vitro assay that recapitulates RNAi in a cell-free system is used to evaluate siNA constructs targeting SCD RNA targets. The assay comprises the system described by Tuschl et al., 1999, Genes and Development, 13, 3191-3197 and Zamore et al., 2000, Cell, 101, 25-33 adapted for use with SCD target RNA. A Drosophila extract derived from syncytial blastoderm is used to reconstitute RNAi activity in vitro. Target RNA is generated via in vitro transcription from an appropriate SCD expressing plasmid using T7 RNA polymerase or via chemical synthesis as described herein. Sense and antisense siNA strands (for example 20 uM each) are annealed by incubation in buffer (such as 100 mM potassium acetate, 30 mM HEPES-KOH, pH 7.4, 2 mM magnesium acetate) for 1 minute at 90° C. followed by 1 hour at 37° C., then diluted in lysis buffer (for example 100 mM potassium acetate, 30 mM HEPES-KOH at pH 7.4, 2 mM magnesium acetate). Annealing can be monitored by gel electrophoresis on an agarose gel in TBE buffer and stained with ethidium bromide. The Drosophila lysate is prepared using zero to two-hour-old embryos from Oregon R flies collected on yeasted molasses agar that are dechorionated and lysed. The lysate is centrifuged and the supernatant isolated. The assay comprises a reaction mixture containing 50% lysate [vol/vol], RNA (10-50 μM final concentration), and 10% [vol/vol] lysis buffer containing siNA (10 nM final concentration). The reaction mixture also contains 10 mM creatine phosphate, 10 ug/ml creatine phosphokinase, 100 um GTP, 100 uM UTP, 100 uM CTP, 500 uM ATP, 5 mM DTT, 0.1 U/uL RNasin (Promega), and 100 uM of each amino acid. The final concentration of potassium acetate is adjusted to 100 mM. The reactions are pre-assembled on ice and preincubated at 25° C. for 10 minutes before adding RNA, then incubated at 25° C. for an additional 60 minutes. Reactions are quenched with 4 volumes of 1.25× Passive Lysis Buffer (Promega). Target RNA cleavage is assayed by RT-PCR analysis or other methods known in the art and are compared to control reactions in which siNA is omitted from the reaction.

Alternately, internally-labeled target RNA for the assay is prepared by in vitro transcription in the presence of [alpha-³²P] CTP, passed over a G50 Sephadex column by spin chromatography and used as target RNA without further purification. Optionally, target NA is 5′-³²P-end labeled using T4 polynucleotide kinase enzyme. Assays are performed as described above and target RNA and the specific RNA cleavage products generated by RNAi are visualized on an autoradiograph of a gel. The percentage of cleavage is determined by PHOSPHOR IMAGER® (autoradiography) quantitation of bands representing intact control RNA or RNA from control reactions without siNA and the cleavage products generated by the assay.

In one embodiment, this assay is used to determine target sites in the SCD RNA target for siNA mediated RNAi cleavage, wherein a plurality of siNA constructs are screened for RNAi mediated cleavage of the SCD RNA target, for example, by analyzing the assay reaction by electrophoresis of labeled target RNA, or by Northern blotting, as well as by other methodology well known in the art.

Example 7 Nucleic Acid Inhibition of SCD Target RNA

siNA molecules targeted to the human SCD RNA are designed and synthesized as described above. These nucleic acid molecules can be tested for cleavage activity in vivo, for example, using the following procedure. The target sequences and the nucleotide location within the SCD RNA are given in Tables II and III.

Two formats are used to test the efficacy of siNAs targeting SCD. First, the reagents are tested in cell culture using, for example, HepG2, MDA-MB-231 or A549 cells, to determine the extent of RNA and protein inhibition. siNA reagents (e.g.; see Tables II and III) are selected against the SCD target as described herein. RNA inhibition is measured after delivery of these reagents by a suitable transfection agent to, for example, HepG2, MDA-MB-231 or A549 cells. Relative amounts of target RNA are measured versus actin using real-time PCR monitoring of amplification (e.g., ABI 7700 TAQMAN®). A comparison is made to a mixture of oligonucleotide sequences made to unrelated targets or to a randomized siNA control with the same overall length and chemistry, but randomly substituted at each position. Primary and secondary lead reagents are chosen for the target and optimization performed. After an optimal transfection agent concentration is chosen, a RNA time-course of inhibition is performed with the lead siNA molecule. In addition, a cell-plating format can be used to determine RNA inhibition.

Delivery of siNA to Cells

Cells such as HepG2, MDA-MB-231 or A549 cells are seeded, for example, at 1×10⁵ cells per well of a six-well dish in EGM-2 (BioWhittaker) the day before transfection. siNA (final concentration, for example 20 nM) and cationic lipid (e.g., final concentration 2 μg/ml) are complexed in EGM basal media (Bio Whittaker) at 37° C. for 30 minutes in polystyrene tubes. Following vortexing, the complexed siNA is added to each well and incubated for the times indicated. For initial optimization experiments, cells are seeded, for example, at 1×10³ in 96 well plates and siNA complex added as described. Efficiency of delivery of siNA to cells is determined using a fluorescent siNA complexed with lipid. Cells in 6-well dishes are incubated with siNA for 24 hours, rinsed with PBS and fixed in 2% paraformaldehyde for 15 minutes at room temperature. Uptake of siNA is visualized using a fluorescent microscope.

TAQMAN® (Real-Time PCR Monitoring of Amplification) and Lightcycler Quantification of mRNA

Total RNA is prepared from cells following siNA delivery, for example, using Qiagen RNA purification kits for 6-well or Rneasy extraction kits for 96-well assays. For TAQMAN® analysis (real-time PCR monitoring of amplification), dual-labeled probes are synthesized with the reporter dye, FAM or JOE, covalently linked at the 5′-end and the quencher dye TAMRA conjugated to the 3′-end. One-step RT-PCR amplifications are performed on, for example, an ABI PRISM 7700 Sequence Detector using 50 μl reactions consisting of 10 μl total RNA, 100 nM forward primer, 900 nM reverse primer, 100 nM probe, 1× TaqMan PCR reaction buffer (PE-Applied Biosystems), 5.5 mM MgCl₂, 300 μM each dATP, dCTP, dGTP, and dTTP, 10U RNase Inhibitor (Promega), 1.25U AMPLITAQ GOLD® (DNA polymerase) (PE-Applied Biosystems) and 10U M-MLV Reverse Transcriptase (Promega). The thermal cycling conditions can consist of 30 minutes at 48° C., 10 minutes at 95° C., followed by 40 cycles of 15 seconds at 95° C. and 1 minute at 60° C. Quantitation of mRNA levels is determined relative to standards generated from serially diluted total cellular RNA (300, 100, 33, 11 ng/r×n) and normalizing to β-actin or GAPDH mRNA in parallel TAQMAN® reactions (real-time PCR monitoring of amplification). For each gene of interest an upper and lower primer and a fluorescently labeled probe are designed. Real time incorporation of SYBR Green I dye into a specific PCR product can be measured in glass capillary tubes using a lightcyler. A standard curve is generated for each primer pair using control cRNA. Values are represented as relative expression to GAPDH in each sample.

Western Blotting

Nuclear extracts can be prepared using a standard micro preparation technique (see for example Andrews and Faller, 1991, Nucleic Acids Research, 19, 2499). Protein extracts from supernatants are prepared, for example using TCA precipitation. An equal volume of 20% TCA is added to the cell supernatant, incubated on ice for 1 hour and pelleted by centrifugation for 5 minutes. Pellets are washed in acetone, dried and resuspended in water. Cellular protein extracts are run on a 10% Bis-Tris NuPage (nuclear extracts) or 4-12% Tris-Glycine (supernatant extracts) polyacrylamide gel and transferred onto nitro-cellulose membranes. Non-specific binding can be blocked by incubation, for example, with 5% non-fat milk for 1 hour followed by primary antibody for 16 hour at 4° C. Following washes, the secondary antibody is applied, for example (1:10,000 dilution) for 1 hour at room temperature and the signal detected with SuperSignal reagent (Pierce).

Example 8 Models Useful to Evaluate the Down-Regulation of SCD Gene Expression Cell Culture

There are numerous cell culture systems that can be used to analyze reduction of SCD levels either directly or indirectly by measuring downstream effects. For example, cultured HepG2, MDA-MB-231 or A549 cells can be used in cell culture experiments to assess the efficacy of nucleic acid molecules of the invention. As such, cells treated with nucleic acid molecules of the invention (e.g., siNA) targeting SCD RNA would be expected to have decreased SCD expression capacity compared to matched control nucleic acid molecules having a scrambled or inactive sequence. In a non-limiting example, cells are cultured and SCD expression is quantified, for example, by time-resolved immuno fluorometric assay. SCD messenger-RNA expression is quantitated with RT-PCR in cultured cells. Untreated cells are compared to cells treated with siNA molecules transfected with a suitable reagent, for example a cationic lipid such as lipofectamine, and SCD protein and RNA levels are quantitated. Dose response assays are then performed to establish dose dependent inhibition of SCD expression.

Liver stearoyl-CoA desaturase (SCD) activity has been implicated in excessive adiposity in chickens. Studies suggest that the difference in SCD activity between fat and lean chickens is explained by a difference in SCD1 gene expression. (Lefevre et al., 1999, Archives of Biochemistry and Biophysics, 368, 329-337). Lefevre et al. describe a study using primary cultures of 6-week-old chicken hepatocytes, in which SCD1 gene expression was analyzed as the result of insulin and glucagon action. The studies showed that insulin increased SCD1 activity and mRNA levels, whereas glucagon dramatically decreased both SCD1 enzyme activity and SCD1 mRNA levels. Nuclear run-on transcription assays and mRNA stability investigations demonstrated that insulin and glucagon effects on SCD1 gene expression were primarily transcriptional in nature. Furthermore, the results indicated that the glucagon-mediated inhibition of SCD1 gene transcription was more potent than simply counteracting the insulin-mediated effect. Moreover, among hepatic genes involved in lipid metabolism in chickens, SCD1 was the first gene shown to be regulated at the transcriptional level by insulin, in the absence of triiodothyronine. These studies demonstrate that the growing chicken hepatocyte culture model is a useful model in studying the effect of SCD inhibitors, including siNA molecules of the present invention.

In several cell culture systems, cationic lipids have been shown to enhance the bioavailability of oligonucleotides to cells in culture (Bennet, et al., 1992, Mol. Pharmacology, 41, 1023-1033). In one embodiment, siNA molecules of the invention are complexed with cationic lipids for cell culture experiments. siNA and cationic lipid mixtures are prepared in serum-free DMEM immediately prior to addition to the cells. DMEM plus additives are warmed to room temperature (about 20-25° C.) and cationic lipid is added to the final desired concentration and the solution is vortexed briefly. siNA molecules are added to the final desired concentration and the solution is again vortexed briefly and incubated for 10 minutes at room temperature. In dose response experiments, the RNA/lipid complex is serially diluted into DMEM following the 10 minute incubation.

Evaluating the efficacy of anti-SCD agents in animal models is an important prerequisite to human clinical trials. Stearoyl-CoA desaturase (SCD) mRNA is overexpressed in various animal models of obesity and type 2 diabetes, see for example Ntambi et al., 2000, Biomedical and Health Research, 37, 69-78 and Miyazaki et al., 2001, J. Biol. Chem., 276, 39455-39461. SCD expression is known to dramatically increase during the differentiation of preadipocytes into adipocytes. Thiazolidinediones (TZDs), ligands for the adipocyte-specific nuclear peroxisome proliferator-activated receptor gamma 2 (PPAR-gamma-2), enhance the conversion of preadipocytes into mature adipocytes in vivo and in vitro, and can exert potent antidiabetic effects by enhancing sensitivity to insulin in target tissues. TZDs have been shown to repress the expression of the SCD1 gene isoform in differentiating preadipocytes and mature adipocytes (Ntambi et al., 2000, Biomedical and Health Research, 37, 69-78). The repression of several other adipogenic genes, including the SCD2 isoform, were not affected by TZDs. In differentiating preadipocytes and mature adipocytes, the downregulation of the SCD1 gene expression was accompanied by a decrease in SCD protein and enzyme activity, as well as a dramatic decrease in palmitoleate (C16:1n-7) composition. The adipocytes were smaller in size and contained smaller fat droplets as observed by Oil Red 0 staining. These data indicate that the TZDs specifically target SCD1 gene expression in both differentiating and mature adipocytes, which consequently decreases the C16:1n-7 composition of triglycerides. The models described by Ntambi et al., 2000, Biomedical and Health Research, 37, 69-78; Miyazaki et al., 2001, J. Biol. Chem., 276, 39455-39461; and Zheng et al., 1999, Nature Genetics, 23, 268-270, such as asebia mouse strains (ab^(j) and ab^(2j)) and mouse models with a targeted disruption (SCD1 −/−) can be used to study the effect of SCD inhibition using siNA molecules of the invention.

Example 9 RNAi Mediated Inhibition of SCD Expression

siNA constructs (Table III) are tested for efficacy in reducing SCD RNA expression in, for example, HepG2, MDA-MB-231 or A549 cells. Cells are plated approximately 24 hours before transfection in 96-well plates at 5,000-7,500 cells/well, 100 μl/well, such that at the time of transfection cells are 70-90% confluent. For transfection, annealed siNAs are mixed with the transfection reagent (Lipofectamine 2000, Invitrogen) in a volume of 50 μl/well and incubated for 20 minutes at room temperature. The siNA transfection mixtures are added to cells to give a final siNA concentration of 25 nM in a volume of 150 μl. Each siNA transfection mixture is added to 3 wells for triplicate siNA treatments. Cells are incubated at 37° for 24 hours in the continued presence of the siNA transfection mixture. At 24 hours, RNA is prepared from each well of treated cells. The supernatants with the transfection mixtures are first removed and discarded, then the cells are lysed and RNA prepared from each well. Target gene expression following treatment is evaluated by RT-PCR for the target gene and for a control gene (36B4, an RNA polymerase subunit) for normalization. The triplicate data is averaged and the standard deviations determined for each treatment. Normalized data are graphed and the percent reduction of target mRNA by active siNAs in comparison to their respective inverted control siNAs is determined.

In a non-limiting example, chemically modified siNA constructs (Table III) were tested for efficacy as described above in reducing SCD RNA expression in A549 cells. Active siNAs were evaluated compared to untreated cells, a matched chemistry irrelevant control (IC, 32072/32075), and a transfection control. Results are summarized in FIG. 22. FIG. 22 shows results for chemically modified siNA constructs targeting various sites in SCD mRNA. As shown in FIG. 22, the active siNA constructs provide significant inhibition of SCD gene expression in cell culture experiments as determined by levels of SCD mRNA when compared to appropriate controls.

Example 10 Indications

The present body of knowledge in SCD research indicates the need for methods to assay SCD activity and for compounds that can regulate SCD expression for research, diagnostic, and therapeutic use. As described herein, the nucleic acid molecules of the present invention can be used in assays to diagnose disease state related of SCD levels. In addition, the nucleic acid molecules can be used to treat disease state related to SCD levels.

Particular conditions and disease states that can be associated with SCD expression modulation include, but are not limited to diabetes (type I and/or type II), atherosclerosis, cancer, obesity, and viral infection, and any other diseases, conditions or disorders that are related to or will respond to the levels of SCD in a cell or tissue, alone or in combination with other therapies.

Thiazolidinediones (TZDs), insulin, and PTP-1B inhibitors (see for example McSwiggen, U.S. Ser. No. 10/206,705) are non-limiting examples of pharmaceutical agents that can be combined with or used in conjunction with the nucleic acid molecules (e.g. siRNA molecules) of the instant invention. Those skilled in the art will recognize that other drugs, such as anti-diabetes and anti-obesity compounds and therapies, can similarly be readily combined with the nucleic acid molecules of the instant invention (e.g. siRNA molecules) and are hence within the scope of the instant invention.

Example 11 Diagnostic Uses

The siNA molecules of the invention can be used in a variety of diagnostic applications, such as in the identification of molecular targets (e.g., RNA) in a variety of applications, for example, in clinical, industrial, environmental, agricultural and/or research settings. Such diagnostic use of siNA molecules involves utilizing reconstituted RNAi systems, for example, using cellular lysates or partially purified cellular lysates. siNA molecules of this invention can be used as diagnostic tools to examine genetic drift and mutations within diseased cells or to detect the presence of endogenous or exogenous, for example viral, RNA in a cell. The close relationship between siNA activity and the structure of the target RNA allows the detection of mutations in any region of the molecule, which alters the base-pairing and three-dimensional structure of the target RNA. By using multiple siNA molecules described in this invention, one can map nucleotide changes, which are important to RNA structure and function in vitro, as well as in cells and tissues. Cleavage of target RNAs with siNA molecules can be used to inhibit gene expression and define the role of specified gene products in the progression of disease or infection. In this manner, other genetic targets can be defined as important mediators of the disease. These experiments will lead to better treatment of the disease progression by affording the possibility of combination therapies (e.g., multiple siNA molecules targeted to different genes, siNA molecules coupled with known small molecule inhibitors, or intermittent treatment with combinations siNA molecules and/or other chemical or biological molecules). Other in vitro uses of siNA molecules of this invention are well known in the art, and include detection of the presence of mRNAs associated with a disease, infection, or related condition. Such RNA is detected by determining the presence of a cleavage product after treatment with an siNA using standard methodologies, for example, fluorescence resonance emission transfer (FRET).

In a specific example, siNA molecules that cleave only wild-type or mutant forms of the target RNA are used for the assay. The first siNA molecules (i.e., those that cleave only wild-type forms of target RNA) are used to identify wild-type RNA present in the sample and the second siNA molecules (i.e., those that cleave only mutant forms of target RNA) are used to identify mutant RNA in the sample. As reaction controls, synthetic substrates of both wild-type and mutant RNA are cleaved by both siNA molecules to demonstrate the relative siNA efficiencies in the reactions and the absence of cleavage of the “non-targeted” RNA species. The cleavage products from the synthetic substrates also serve to generate size markers for the analysis of wild-type and mutant RNAs in the sample population. Thus, each analysis requires two siNA molecules, two substrates and one unknown sample, which is combined into six reactions. The presence of cleavage products is determined using an RNase protection assay so that full-length and cleavage fragments of each RNA can be analyzed in one lane of a polyacrylamide gel. It is not absolutely required to quantify the results to gain insight into the expression of mutant RNAs and putative risk of the desired phenotypic changes in target cells. The expression of mRNA whose protein product is implicated in the development of the phenotype (i.e., disease related or infection related) is adequate to establish risk. If probes of comparable specific activity are used for both transcripts, then a qualitative comparison of RNA levels is adequate and decreases the cost of the initial diagnosis. Higher mutant form to wild-type ratios are correlated with higher risk whether RNA levels are compared qualitatively or quantitatively.

All patents and publications mentioned in the specification are indicative of the levels of skill of those skilled in the art to which the invention pertains. All references cited in this disclosure are incorporated by reference to the same extent as if each reference had been incorporated by reference in its entirety individually.

One skilled in the art would readily appreciate that the present invention is well adapted to carry out the objects and obtain the ends and advantages mentioned, as well as those inherent therein. The methods and compositions described herein as presently representative of preferred embodiments are exemplary and are not intended as limitations on the scope of the invention. Changes therein and other uses will occur to those skilled in the art, which are encompassed within the spirit of the invention, are defined by the scope of the claims.

It will be readily apparent to one skilled in the art that varying substitutions and modifications can be made to the invention disclosed herein without departing from the scope and spirit of the invention. Thus, such additional embodiments are within the scope of the present invention and the following claims. The present invention teaches one skilled in the art to test various combinations and/or substitutions of chemical modifications described herein toward generating nucleic acid constructs with improved activity for mediating RNAi activity. Such improved activity can comprise improved stability, improved bioavailability, and/or improved activation of cellular responses mediating RNAi. Therefore, the specific embodiments described herein are not limiting and one skilled in the art can readily appreciate that specific combinations of the modifications described herein can be tested without undue experimentation toward identifying siNA molecules with improved RNAi activity.

The invention illustratively described herein suitably can be practiced in the absence of any element or elements, limitation or limitations that are not specifically disclosed herein. Thus, for example, in each instance herein any of the terms “comprising”, “consisting essentially of”, and “consisting of” may be replaced with either of the other two terms. The terms and expressions which have been employed are used as terms of description and not of limitation, and there is no intention that in the use of such terms and expressions of excluding any equivalents of the features shown and described or portions thereof, but it is recognized that various modifications are possible within the scope of the invention claimed. Thus, it should be understood that although the present invention has been specifically disclosed by preferred embodiments, optional features, modification and variation of the concepts herein disclosed may be resorted to by those skilled in the art, and that such modifications and variations are considered to be within the scope of this invention as defined by the description and the appended claims.

In addition, where features or aspects of the invention are described in terms of Markush groups or other grouping of alternatives, those skilled in the art will recognize that the invention is also thereby described in terms of any individual member or subgroup of members of the Markush group or other group.

TABLE I SCD Accession Numbers XM_208174 Homo sapiens similar to stearoyl-CoA desaturase (delta-9-desaturase) [Homo sapiens] (LOC284202), mRNA gi|27500564|ref|XM_208174.1|[27500564] NM_005063 Homo sapiens stearoyl-CoA desaturase (delta-9- desaturase) (SCD), mRNA gi|19923295|ref|NM_005063.2|[19923295] Y13647 Homo sapiens mRNA for stearoyl-CoA desaturase gi|2190403|emb|Y13647.1|HSSTEACOA[2190403] AF320307 Homo sapiens stearoyl-CoA desaturase (SCD) gene, exon 1 and intron 1 and partial cds gi|14150490|gb|AF320307.1|AF320307[14150490] AU098830 AU098830 Sugano Homo sapiens cDNA library Homo sapiens cDNA clone HEP02242 similar to Homo sapiens stearoyl-CoA desaturase (SCD) mRNA, MRNA sequence gi|13549959|dbj|AU098830.1|[13549959] BG319495 Tmdh05 Human Keratinocyte Subtraction Library- Downregulated Transcripts Homo sapiens cDNA similar to stearoyl-CoA desaturase (delta-9-desaturase) (SCD), MRNA sequence gi|13129361|gb|BG319495.1|[13129361] BG319433 4dh85 Human Keratinocyte Subtraction Library- Downregulated Transcripts Homo sapiens cDNA similar to stearoyl-CoA desaturase (SCD), MRNA sequence gi|13129299|gb|BG319433.1|[13129299] AU076658 AU076658 Sugano cDNA library Homo sapiens cDNA clone HEP02242 similar to 5′-end region of Homo sapiens mRNA for stearoyl-CoA desaturase, MRNA sequence gi|7439136|dbj|AU076658.1|[7439136] AB032261 Homo sapiens Scd mRNA for stearoyl-CoA desaturase, complete cds gi|7415720|dbj|AB032261.1|[7415720] AF097514 Homo sapiens stearoyl-CoA desaturase (SCD) mRNA, complete cds gi|4808600|gb|AF097514.1|AF097514[4808600] S70284 stearoyl-CoA desaturase [human, adipose tissue, mRNA Partial, 712 nt] gi|546517|bbm|339737|bbs|148167|gb|S70284.1|S70284[546517]

TABLE II SCD siNA AND TARGET SEQUENCES SCD NM_005063.2 Pos Seq Seq ID UPos Upper seq Seq ID LPos Lower seq Seq ID    3 AAAAGGGGGCUGAGGAAAU   1    3 AAAAGGGGGCUGAGGAAAU   1   21 AUUUCCUCAGCCCCCUUUU 291   21 UACCGGACACGGUCACCCG   2   21 UACCGGACACGGUGACCCG   2   39 CGGGUGACCGUGUCCGGUA 292   39 GUUGCCAGCUCUAGCCUUU   3   39 GUUGCCAGCUCUAGCCUUU   3   57 AAAGGCUAGAGCUGGCAAC 293   57 UAAAUUCCCGGCUCGGGGA   4   57 UAAAUUCCCGGCUCGGGGA   4   75 UCCCCGAGCCGGGAAUUUA 294   75 ACCUCCACGCACCGCGGCU   5   75 ACCUCCACGCACCGCGGCU   5   93 AGCCGCGGUGCGUGGAGGU 295   93 UAGCGCCGACAACCAGCUA   6   93 UAGCGGCGACAACCAGCUA   6  111 UAGCUGGUUGUCGGCGCUA 296  111 AGCGUGCAAGGCGCCGCGG   7  111 AGCGUGCAAGGCGCCGCGG   7  129 CCGCGGCGCCUUGCACGCU 297  129 GCUCAGCGCGUACCGGCGG   8  129 GCUCAGCGCGUACCGGCGG   8  147 CCGCCGGUACGCGCUGAGC 298  147 GGCUUCGAAACCGCAGUCC   9  147 GGCUUCGAAACCGCAGUCC   9  165 GGACUGCGGUUUCGAAGCC 299  165 CUCCGGCGACCCCGAACUC  10  165 CUCCGGCGACCCCGAACUC  10  183 GAGUUCGGGGUCGCCGGAG 300  183 CCGCUCCGGAGCCUCAGCC  11  183 CCGCUCCGGAGCCUCAGCC  11  201 GGCUGAGGCUCCGGAGCGG 301  201 CCCCUGGAAAGUGAUCCCG  12  201 CCCCUGGAAAGUGAUCCCG  12  219 CGGGAUCACUUUCCAGGGG 302  219 GGCAUCCGAGAGCCAAGAU  13  219 GGCAUCCGAGAGCCAAGAU  13  237 AUCUUGGCUCUCGGAUGCC 303  237 UGCCGGCCCACUUGCUGCA  14  237 UGCCGGCCCACUUGCUGGA  14  255 UGCAGCAAGUGGGCCGGCA 304  255 AGGACGAUAUCUCUAGCUC  15  255 AGGACGAUAUCUCUAGCUC  15  273 GAGCUAGAGAUAUCGUCCU 305  273 CCUAUACCACCACCACCAC  16  273 CCUAUACCACCACCACCAC  16  291 GUGGUGGUGGUGGUAUAGG 306  291 CCAUUACAGCGCCUCCCUC  17  291 CCAUUACAGCGCCUCCCUC  17  309 GAGGGAGGCGCUGUAAUGG 307  309 CCAGGGUCCUGCAGAAUGG  18  309 CCAGGGUCCUGCAGAAUGG  18  327 CCAUUCUGCAGGACCCUGG 308  327 GAGGAGAUAAGUUGGAGAC  19  327 GAGGAGAUAAGUUGGAGAC  19  345 GUCUCCAACUUAUCUCCUG 309  345 CGAUGCCCCUCUACUUGGA  20  345 CGAUGCCCCUCUACUUGGA  20  363 UCCAAGUAGAGGGGCAUCG 310  363 AAGACGACAUUCGCCCUGA  21  363 AAGACGACAUUCGCCCUGA  21  381 UCAGGGCGAAUGUCGUCUU 311  381 AUAUAAAAGAUGAUAUAUA  22  381 AUAUAAAAGAUGAUAUAUA  22  399 UAUAUAUCAUCUUUUAUAU 312  399 AUGACCCCACCUACAAGGA  23  399 AUGACCCCACCUACAAGGA  23  417 UCCUUGUAGGUGGGGUCAU 313  417 AUAAGGAAGGCCCAAGCCC  24  417 AUAAGGAAGGCCCAAGCCC  24  435 GGGCUUGGGCCUUCCUUAU 314  435 CCAAGGUUGAAUAUGUCUG  25  435 CCAAGGUUGAAUAUGUCUG  25  453 CAGACAUAUUCAACCUUGG 315  453 GGAGAAACAUCAUCCUUAU  26  453 GGAGAAACAUCAUCCUUAU  26  471 AUAAGGAUGAUGUUUCUCC 316  471 UGUCUCUGCUACACUUGGG  27  471 UGUCUCUGCUACACUUGGG  27  489 CCCAAGUGUAGCAGAGACA 317  489 GAGCCCUGUAUGGGAUCAC  28  489 GAGCCCUGUAUGGGAUCAC  28  507 GUGAUCCCAUACAGGGCUC 318  507 CUUUGAUUCCUACCUGCAA  29  507 CUUUGAUUCCUACCUGCAA  29  525 UUGCAGGUAGGAAUCAAAG 319  525 AGUUCUACACCUGGCUUUG  30  525 AGUUCUACACCUGGCUUUG  30  543 CAAAGCCAGGUGUAGAACU 320  543 GGGGGGUAUUCUACUAUUU  31  543 GGGGGGUAUUCUACUAUUU  31  561 AAAUAGUAGAAUACCCCCC 321  561 UUGUCAGUGCCCUGGGCAU  32  561 UUGUCAGUGCCCUGGGCAU  32  579 AUGCCCAGGGCACUGACAA 322  579 UAACAGCAGGAGCUCAUCG  33  579 UAACAGCAGGAGCUCAUCG  33  597 CGAUGAGCUCCUGCUGUUA 323  597 GUGUGUGGAGCCAGCGGUC  34  597 GUCUGUGGAGCCACCGCUC  34  615 GAGCGGUGGCUCCACAGAC 324  615 CUUACAAAGCUCGGCUGCC  35  615 CUUACAAAGCUCGGCUGCC  35  633 GGCAGCCGAGCUUUGUAAG 325  633 CCCUACGGCUCUUUCUGAU  36  633 CCCUACGGCUCUUUCUGAU  36  651 AUCAGAAAGAGCCGUAGGG 326  651 UCAUUGCCAACACAAUGGC  37  651 UCAUUGCCAACACAAUGGC  37  669 GCCAUUGUGUUGGCAAUGA 327  669 CAUUCCAGAAUGAUGUCUA  38  669 CAUUCCAGAAUGAUGUCUA  38  687 UAGACAUCAUUCUGGAAUG 328  687 AUGAAUGGGCUCGUGACCA  39  687 AUGAAUGGGCUCGUGACCA  39  705 UGGUCACGAGCCCAUUCAU 329  705 ACCGUGCCCACCACAAGUU  40  705 ACCGUGCCCACCACAAGUU  40  723 AACUUGUGGUGGGCACGGU 330  723 UUUCAGAAACACAUGCUGA  41  723 UUUCAGAAACACAUGCUGA  41  741 UCAGCAUGUGUUUCUGAAA 331  741 AUCCUCAUAAUUCCCGACG  42  741 AUCCUCAUAAUUCCCGACG  42  759 CGUCGGGAAUUAUGAGGAU 332  759 GUGGCUUUUUCUUCUCUCA  43  759 GUGGCUUUUUCUUCUCUCA  43  777 UGAGAGAAGAAAAAGCCAC 333  777 ACGUGGGUUGGCUGCUUGU  44  777 ACGUGGGUUGGCUGCUUGU  44  795 ACAAGCAGCCAACCCACGU 334  795 UGCGCAAACACCCAGCUGU  45  795 UGCGCAAACACCCAGCUGU  45  813 ACAGCUGGGUGUUUGCGCA 335  813 UCAAAGAGAAGGGGAGUAC  46  813 UCAAAGAGAAGGGGAGUAC  46  831 GUACUCCCCUUCUCUUUGA 336  831 CGCUAGACUUGUCUGACCU  47  831 CGCUAGACUUGUCUGACCU  47  849 AGGUCAGACAAGUCUAGCG 337  849 UAGAAGCUGAGAAACUGGU  48  849 UAGAAGCUGAGAAACUGGU  48  867 ACCAGUUUCUCAGCUUCUA 338  867 UGAUGUUCCAGAGGAGGUA  49  867 UGAUGUUCCAGAGGAGGUA  49  885 UACCUCCUCUGGAACAUCA 339  885 ACUACAAACCUGGCUUGCU  50  885 ACUACAAACCUGGCUUGCU  50  903 AGCAAGCCAGGUUUGUAGU 340  903 UGCUGAUGUGCUUCAUCCU  51  903 UGCUGAUGUGCUUCAUCCU  51  921 AGGAUGAAGCACAUCAGCA 341  921 UGCCCACGCUUGUGCCCUG  52  921 UGCCCACGCUUGUGCCCUG  52  939 CAGGGCACAAGCGUGGGCA 342  939 GGUAUUUCUGGGGUGAAAC  53  939 GGUAUUUCUGGGGUGAAAC  53  957 GUUUCACCCCAGAAAUACC 343  957 CUUUUCAAAACAGUGUGUU  54  957 CUUUUCAAAACAGUGUGUU  54  975 AACACACUGUUUUGAAAAG 344  975 UCGUUGCCACUUUCUUGCG  55  975 UCGUUGCCACUUUCUUGCG  55  993 CGCAAGAAAGUGGCAACGA 345  993 GAUAUGCUGUGGUGCUUAA  56  993 GAUAUGCUGUGGUGCUUAA  56 1011 UUAAGCACCACAGCAUAUC 346 1011 AUGCCACCUGGCUGGUGAA  57 1011 AUGCCACCUGGCUGGUGAA  57 1029 UUCACCAGCCAGGUGGCAU 347 1029 ACAGUGCUGCCCACCUCUU  58 1029 ACAGUGCUGCCCACCUCUU  58 1047 AAGAGGUGGGCAGCACUGU 348 1047 UCGGAUAUCGUCCUUAUGA  59 1047 UCGGAUAUCGUCCUUAUGA  59 1065 UCAUAAGGACGAUAUCCGA 349 1065 ACAAGAACAUUAGCCCCCG  60 1065 ACAAGAACAUUAGCCCCCG  60 1083 CGGGGGCUAAUGUUCUUGU 350 1083 GGGAGAAUAUCCUGGUUUC  61 1083 GGGAGAAUAUCCUGGUUUC  61 1101 GAAACCAGGAUAUUCUCCC 351 1101 CACUUGGAGCUGUGGGUGA  62 1101 CACUUGGAGCUGUGGGUGA  62 1119 UCACCCACAGCUCCAAGUG 352 1119 AGGGCUUCCACAACUACCA  63 1119 AGGGCUUCCACAACUACCA  63 1137 UGGUAGUUGUGGAAGCCCU 353 1137 ACCACUCCUUUCCCUAUGA  64 1137 ACCACUCCUUUCCCUAUGA  64 1155 UCAUAGGGAAAGGAGUGGU 354 1155 ACUACUCUGCCAGUGAGUA  65 1155 ACUACUCUGCCAGUGAGUA  65 1173 UACUCACUGGCAGAGUAGU 355 1173 ACCGCUGGCACAUCAACUU  66 1173 ACCGCUGGCACAUCAACUU  66 1191 AAGUUGAUGUGCCAGCGGU 356 1191 UCACCACAUUCUUCAUUGA  67 1191 UCACCACAUUCUUCAUUGA  67 1209 UCAAUGAAGAAUGUGGUGA 357 1209 AUUGCAUGGCCGCCCUCGG  68 1209 AUUGCAUGGCCGCCCUCGG  68 1227 CCGAGGGCGGCCAUGCAAU 358 1227 GUCUGGCCUAUGACCGGAA  69 1227 GUCUGGCCUAUGACCGGAA  69 1245 UUCCGGUCAUAGGCCAGAC 359 1245 AGAAAGUCUCCAAGGCCGC  70 1245 AGAAAGUCUCCAAGGCCGC  70 1263 GCGGCCUUGGAGACUUUCU 360 1263 CCAUCUUGGCCAGGAUUAA  71 1263 CCAUCUUGGCCAGGAUUAA  71 1281 UUAAUCCUGGCCAAGAUGG 361 1281 AAAGAACCGGAGAUGGAAA  72 1281 AAAGAACCGGAGAUGGAAA  72 1299 UUUCCAUCUCCGGUUCUUU 362 1299 ACUACAAGAGUGGCUGAGU  73 1299 ACUACAAGAGUGGCUGAGU  73 1317 ACUCAGCCACUCUUGUAGU 363 1317 UUUGGGGUCCCUCAGGUUU  74 1317 UUUGGGGUCCCUCAGGUUU  74 1335 AAACCUGAGGGACCCCAAA 364 1335 UCCUUUUUCAAAAACCAGC  75 1335 UCCUUUUUCAAAAACCAGC  75 1353 GCUGGUUUUUGAAAAAGGA 365 1353 CCAGGCAGAGGUUUUAAUG  76 1353 CCAGGCAGAGGUUUUAAUG  76 1371 CAUUAAAACCUCUGCCUGG 366 1371 GUCUGUUUAUUAACUACUG  77 1371 GUCUGUUUAUUAACUACUG  77 1389 CAGUAGUUAAUAAACAGAC 367 1389 GAAUAAUGCUACCAGGAUG  78 1389 GAAUAAUGCUACCAGGAUG  78 1407 CAUCCUGGUAGCAUUAUUC 368 1407 GCUAAAGAUGAUGAUGUUA  79 1407 GCUAAAGAUGAUGAUGUUA  79 1425 UAACAUCAUCAUCUUUAGC 369 1425 AACCCAUUCCAGUACAGUA  80 1425 AACCCAUUCCAGUACAGUA  80 1443 UACUGUACUGGAAUGGGUU 370 1443 AUUCUUUUAAAAUUCAAAA  81 1443 AUUCUUUUAAAAUUCAAAA  81 1461 UUUUGAAUUUUAAAAGAAU 371 1461 AGUAUUGAAAGCCAACAAC  82 1461 AGUAUUGAAAGCCAACAAC  82 1479 GUUGUUGGCUUUCAAUACU 372 1479 CUCUGCCUUUAUGAUGCUA  83 1479 CUCUGCCUUUAUGAUGCUA  83 1497 UAGCAUCAUAAAGGCAGAG 373 1497 AAGCUGAUAUUAUUUCUUC  84 1497 AAGCUGAUAUUAUUUCUUC  84 1515 GAAGAAAUAAUAUCAGCUU 374 1515 CUCUUAUCCUCUCUCUCUU  85 1515 CUCUUAUCCUCUCUCUCUU  85 1533 AAGAGAGAGAGGAUAAGAG 375 1533 UCUAGGCCCAUUGUCCUCC  86 1533 UCUAGGCCCAUUGUCCUCC  86 1551 GGAGGACAAUGGGCCUAGA 376 1551 CUUUUCACUUUAUUGCUAU  87 1551 CUUUUCACUUUAUUGCUAU  87 1569 AUAGCAAUAAAGUGAAAAG 377 1569 UCGCCCUCCUUUCCCUUAU  88 1569 UCGCCCUCCUUUCCCUUAU  88 1587 AUAAGGGAAAGGAGGGCGA 378 1587 UUGCCUCCCAGGCAAGCAG  89 1587 UUGCCUCCCAGGCAAGCAG  89 1605 CUGCUUGCCUGGGAGGCAA 379 1605 GCUGGUCAGUCUUUGCUCA  90 1605 GCUGGUCAGUCUUUGCUCA  90 1623 UGAGCAAAGACUGACCAGC 380 1623 AGUGUCCAGCUUCCAAAGC  91 1623 AGUGUCCAGCUUCCAAAGC  91 1641 GCUUUGGAAGCUGGACACU 381 1641 CCUAGACAACCUUUCUGUA  92 1641 CCUAGACAACGUUUCUGUA  92 1659 UACAGAAAGGUUGUCUAGG 382 1659 AGCCUAAAACGAAUGGUCU  93 1659 AGCCUAAAACGAAUGGUCU  93 1677 AGACCAUUCGUUUUAGGCU 383 1677 UUUGCUCCAGAUAACUCUC  94 1677 UUUGCUCCAGAUAACUCUC  94 1695 GAGAGUUAUCUGGAGCAAA 384 1695 CUUUCCUUGAGCUGUUGUG  95 1695 CUUUCCUUGAGCUGUUGUG  95 1713 CACAACAGCUCAAGGAAAG 385 1713 GAGCUUUGAAGUAGGUGGC  96 1713 GAGCUUUGAAGUAGGUGGC  96 1731 GCCACCUACUUCAAAGCUC 386 1731 CUUGAGCUAGAGAUAAAAC  97 1731 CUUGAGCUAGAGAUAAAAC  97 1749 GUUUUAUCUCUAGCUCAAG 387 1749 CAGAAUCUUCUGGGUAGUC  98 1749 CAGAAUCUUCUGGGUAGUC  98 1767 GACUACCCAGAAGAUUCUG 388 1767 CCCCUGUUGAUUAUCUUCA  99 1767 CCCCUGUUGAUUAUCUUCA  99 1785 UGAAGAUAAUCAACAGGGG 389 1785 AGCCCAGGCUUUUGCUAGA 100 1785 AGCCCAGGCUUUUGCUAGA 100 1803 UCUAGCAAAAGCCUGGGCU 390 1803 AUGGAAUGGAAAAGCAACU 101 1803 AUGGAAUGGAAAAGCAACU 101 1821 AGUUGCUUUUCCAUUCCAU 391 1821 UUCAUUUGACACAAAGCUU 102 1821 UUCAUUUGACACAAAGCUU 102 1839 AAGCUUUGUGUCAAAUGAA 392 1839 UCUAAAGCAGGUAAAUUGU 103 1839 UCUAAAGCAGGUAAAUUGU 103 1857 ACAAUUUACCUGCUUUAGA 393 1857 UCGGGGGAGAGAGUUAGCA 104 1857 UCGGGGGAGAGAGUUAGCA 104 1875 UGCUAACUCUCUCCCCCGA 394 1875 AUGUAUGAAUGUAAGGAUG 105 1875 AUGUAUGAAUGUAAGGAUG 105 1893 CAUCCUUACAUUCAUACAU 395 1893 GAGGGAAGCGAAGCAAGAG 106 1893 GAGGGAAGCGAAGCAAGAG 106 1911 CUCUUGGUUCGCUUCCCUC 396 1911 GGAACCUCUCGCCAUGAUC 107 1911 GGAACCUCUCGCCAUGAUC 107 1929 GAUCAUGGCGAGAGGUUCC 397 1929 CAGACAUACAGCUGCCUAC 108 1929 CAGACAUACAGCUGCCUAC 108 1947 GUAGGCAGCUGUAUGUCUG 398 1947 CCUAAUGAGGACUUCAAGC 109 1947 CCUAAUGAGGACUUCAAGC 109 1965 GCUUGAAGUCCUCAUUAGG 399 1965 CCCCACCACAUAGCAUGCU 110 1965 CCCCACCACAUAGCAUGCU 110 1983 AGCAUGCUAUGUGGUGGGG 400 1983 UUCCUUUCUCUCCUGGCUC 111 1983 UUCCUUUCUCUCCUGGCUC 111 2001 GAGCCAGGAGAGAAAGGAA 401 2001 CGGGGUAAAAAGUGGCUGC 112 2001 CGGGGUAAAAAGUGGCUGC 112 2019 GCAGCCACUUUUUACCCCG 402 2019 CGGUGUUUGGCAAUGCUAA 113 2019 CGGUGUUUGGCAAUGCUAA 113 2037 UUAGCAUUGCCAAACACCG 403 2037 AUUCAAUGCCGCAACAUAU 114 2037 AUUCAAUGCCGCAACAUAU 114 2055 AUAUGUUGCGGCAUUGAAU 404 2055 UAGUUGAGGCCGAGGAUAA 115 2055 UAGUUGAGGCCGAGGAUAA 115 2073 UUAUCCUCGGCCUCAACUA 405 2073 AAGAAAAGACAUUUUAAGU 116 2073 AAGAAAAGACAUUUUAAGU 116 2091 ACUUAAAAUGUCUUUUCUU 406 2091 UUUGUAGUAAAAGUGGUCU 117 2091 UUUGUAGUAAAAGUGGUCU 117 2109 AGACCACUUUUACUACAAA 407 2109 UCUGCUGGGGAAGGGUUUU 118 2109 UCUGCUGGGGAAGGGUUUU 118 2127 AAAACCCUUCCCCAGCAGA 408 2127 UCUUUUCUUUUUUUCUUUA 119 2127 UCUUUUCUUUUUUUCUUUA 119 2145 UAAAGAAAAAAAGAAAAGA 409 2145 AAUAACAAGGAGAUUUCUU 120 2145 AAUAACAAGGAGAUUUCUU 120 2163 AAGAAAUCUCCUUGUUAUU 410 2163 UAGUUCAUAUAUCAAGAAG 121 2163 UAGUUCAUAUAUCAAGAAG 121 2181 CUUCUUGAUAUAUGAACUA 411 2181 GUCUUGAAGUUGGGUGUUU 122 2181 GUCUUGAAGUUGGGUGUUU 122 2199 AAACACCCAACUUCAAGAC 412 2199 UCCAGAAUUGGUAAAAACA 123 2199 UCCAGAAUUGGUAAAAACA 123 2217 UGUUUUUACCAAUUCUGGA 413 2217 AGCAGCUCAUGGAAUUUUG 124 2217 AGCAGCUCAUGGAAUUUUG 124 2235 CAAAAUUCCAUGAGCUGCU 414 2235 GAGUAUUCCAUGAGCUGCU 125 2235 GAGUAUUCCAUGAGCUGCU 125 2253 AGCAGCUCAUGGAAUACUC 415 2253 UCAUUACAGUUCUUUCCUC 126 2253 UCAUUACAGUUCUUUCCUC 126 2271 GAGGAAAGAACUGUAAUGA 416 2271 CUUUCUGCUCUGCCAUCUU 127 2271 CUUUCUGCUCUGCCAUCUU 127 2289 AAGAUGGCAGAGCAGAAAG 417 2289 UCAGGAUAUUGGUUCUUCC 128 2289 UCAGGAUAUUGGUUCUUCC 128 2307 GGAAGAACCAAUAUCCUGA 418 2307 CCCUCAUAGUAAUAAGAUG 129 2307 CCCUCAUAGUAAUAAGAUG 129 2325 CAUCUUAUUACUAUGAGGG 419 2325 GGCUGUGGCAUUUCCAAAC 130 2325 GGCUGUGGCAUUUCCAAAC 130 2343 GUUUGGAAAUGCCACAGCC 420 2343 CAUCCAAAAAAAGGGAAGG 131 2343 CAUCGAAAAAAAGGGAAGG 131 2361 CCUUCCCUUUUUUUGGAUG 421 2361 GAUUUAAGGAGGUGAAGUC 132 2361 GAUUUAAGGAGGUGAAGUC 132 2379 GACUUCACCUCCUUAAAUC 422 2379 CGGGUCAAAAAUAAAAUAU 133 2379 CGGGUCAAAAAUAAAAUAU 133 2397 AUAUUUUAUUUUUGACCCG 423 2397 UAUAUACAUAUAUACAUUG 134 2397 UAUAUACAUAUAUACAUUG 134 2415 CAAUGUAUAUAUGUAUAUA 424 2415 GCUUAGAACGUUAAACUAU 135 2415 GCUUAGAACGUUAAACUAU 135 2433 AUAGUUUAACGUUCUAAGC 425 2433 UUAGAGUAUUUCCCUUCCA 136 2433 UUAGAGUAUUUCCCUUCCA 136 2451 UGGAAGGGAAAUACUCUAA 426 2451 AAAGAGGGAUGUUUGGAAA 137 2451 AAAGAGGGAUGUUUGGAAA 137 2469 UUUCCAAACAUCCCUCUUU 427 2469 AAAACUCUGAAGGAGAGGA 138 2469 AAAACUCUGAAGGAGAGGA 138 2487 UCCUCUCCUUCAGAGUUUU 428 2487 AGGAAUUAGUUGGGAUGCC 139 2487 AGGAAUUAGUUGGGAUGCC 139 2505 GGCAUCCGAAGUAAUUCCU 429 2505 CAAUUUCCUCUCCACUGCU 140 2505 CAAUUUCCUGUCCACUGCU 140 2523 AGCAGUGGAGAGGAAAUUG 430 2523 UGGACAUGAGAUGGAGAGG 141 2523 UGGACAUGAGAUGGAGAGG 141 2541 CCUCUCCAUCUCAUGUCCA 431 2541 GCUGAGGGACAGGAUCUAU 142 2541 GCUGAGGGACAGGAUCUAU 142 2559 AUAGAUCCUGUCCCUCAGC 432 2559 UAGGCAGCUUCUAAGAGCG 143 2559 UAGGCAGCUUCUAAGAGCG 143 2577 CGCUCUUAGAAGCUGCCUA 433 2577 GAACUUCACAUAGGAAGGG 144 2577 GAACUUCACAUAGGAAGGG 144 2595 CCCUUCCUAUGUGAAGUUC 434 2595 GAUCUGAGAACACGUUGCC 145 2595 GAUCUGAGAACACGUUGCC 145 2613 GGCAACGUGUUCUCAGAUC 435 2613 CAGGGGCUUGAGAAGGUUA 146 2613 CAGGGGCUUGAGAAGGUUA 146 2631 UAACCUUCUCAAGCCCCUG 436 2631 ACUGAGUGAGUUAUUGGGA 147 2631 ACUGAGUGAGUUAUUGGGA 147 2649 UCCCAAUAACUCACUCAGU 437 2649 AGUCUUAAUAAAAUAAACU 148 2649 AGUCUUAAUAAAAUAAACU 148 2667 AGUUUAUUUUAUUAAGACU 438 2667 UAGAUAUUAGGUCCAUUCA 149 2667 UAGAUAUUAGGUCCAUUCA 149 2685 UGAAUGGACCUAAUAUCUA 439 2685 AUUAAUUAGUUCCAGUUUC 150 2685 AUUAAUUAGUUCCAGUUUC 150 2703 GAAACUGGAACUAAUUAAU 440 2703 CUCCUUGAAAUGAGUAAAA 151 2703 CUCCUUGAAAUGAGUAAAA 151 2721 UUUUACUCAUUUCAAGGAG 441 2721 AACUAGAAGGCUUCUCUCC 152 2721 AACUAGAAGGCUUCUCUCC 152 2739 GGAGAGAAGCCUUCUAGUU 442 2739 CACAGUGUUGUGCCCCUUC 153 2739 CACAGUGUUGUGCCCCUUC 153 2757 GAAGGGGCACAACACUGUG 443 2757 CACUCAUUUUUUUUUGAGG 154 2757 CACUCAUUUUUUUUUGAGG 154 2775 CCUCAAAAAAAAAUGAGUG 444 2775 GAGAAGGGGGUCUCUGUUA 155 2775 GAGAAGGGGGUCUCUGUUA 155 2793 UAACAGAGACCCCCUUCUC 445 2793 AACAUCUAGCCUAAAGUAU 156 2793 AACAUCUAGCCUAAAGUAU 156 2811 AUACUUUAGGCUAGAUGUU 446 2811 UACAACUGCCUGGGGGGCA 157 2811 UACAACUGCCUGGGGGGCA 157 2829 UGCCCCCCAGGCAGUUGUA 447 2829 AGGGUUAGGAAUCUCUUCA 158 2829 AGGGUUAGGAAUCUCUUCA 158 2847 UGAAGAGAUUCCUAACCCU 448 2847 ACUACCCUGAUUCUUGAUU 159 2847 ACUACCCUGAUUCUUGAUU 159 2865 AAUCAAGAAUCAGGGUAGU 449 2865 UCCUGGCUCUACCCUGUCU 160 2865 UCCUGGCUCUACCCUGUCU 160 2883 AGACAGGGUAGAGCCAGGA 450 2883 UGUCCCUUUUCUUUGACCA 161 2883 UGUCCCUUUUCUUUGACCA 161 2901 UGGUCAAAGAAAAGGGACA 451 2901 AGAUCUUUCUCUUCCCUGA 162 2901 AGAUCUUUCUCUUCCCUGA 162 2919 UCAGGGAAGAGAAAGAUCU 452 2919 AACGUUUUCUUCUUUCCCU 163 2919 AACGUUUUCUUCUUUCCCU 163 2937 AGGGAAAGAAGAAAACGUU 453 2937 UGGACAGGCAGCCUCCUUU 164 2937 UGGACAGGCAGCCUCCUUU 164 2955 AAAGGAGGCUGCCUGUCCA 454 2955 UGUGUGUAUUCAGAGGCAG 165 2955 UGUGUGUAUUCAGAGGCAG 165 2973 CUGCCUCUGAAUACACACA 455 2973 GUGAUGACUUGCUGUCCAG 166 2973 GUGAUGACUUGCUGUCCAG 166 2991 CUGGACAGCAAGUCAUCAC 456 2991 GGCAGCUCCCUCCUGCACA 167 2991 GGCAGCUCCCUCCUGCACA 167 3009 UGUGCAGGAGGGAGCUGCC 457 3009 ACAGAAUGCUCAGGGUCAC 168 3009 ACAGAAUGCUCAGGGUCAC 168 3027 GUGACCCUGAGCAUUCUGU 458 3027 CUGAACCACUGCUUCUCUU 169 3027 CUGAACCACUGCUUCUCUU 169 3045 AAGAGAAGCAGUGGUUCAG 459 3045 UUUGAAAGUAGAGCUAGCU 170 3045 UUUGAAAGUAGAGCUAGCU 170 3063 AGCUAGCUCUACUUUCAAA 460 3063 UGCCACUUUCACGUGGCCU 171 3063 UGCCACUUUCACGUGGCCU 171 3081 AGGCCACGUGAAAGUGGCA 461 3081 UCCGCAGUGUCUCCACCUA 172 3081 UCCGCAGUGUCUCCACCUA 172 3099 UAGGUGGAGACACUGCGGA 462 3099 ACACCCCUGUGGUCCCCUG 173 3099 ACACCCCUGUGCUCCCCUG 173 3117 CAGGGGAGCACAGGGGUGU 463 3117 GCCACACUGAUGGCUCAAG 174 3117 GCCACACUGAUGGCUCAAG 174 3135 CUUGAGCCAUCAGUGUGGC 464 3135 GACAAGGCUGGCAAACCCU 175 3135 GACAAGGCUGGCAAACCCU 175 3153 AGGGUUUGCCAGCCUUGUC 465 3153 UCCCAGAAACAUCUCUGGC 176 3153 UCCCAGAAACAUCUCUGGC 176 3171 GCCAGAGAUGUUUCUGGGA 466 3171 CCCAGAAAGCCUCUCUCUC 177 3171 CCCAGAAAGCCUCUCUCUC 177 3189 GAGAGAGAGGCUUUCUGGG 467 3189 CCCUCCCUCUCUCAUGAGG 178 3189 CCCUCCCUCUCUCAUGAGG 178 3207 CCUCAUGAGAGAGGGAGGG 468 3207 GCACAGCCAAGCCAAGCGC 179 3207 GCACAGCCAAGCCAAGCGC 179 3225 GCGCUUGGCUUGGCUGUGC 469 3225 CUCAUGUUGAGCCAGUGGG 180 3225 CUCAUGUUGAGCCAGUGGG 180 3243 CCCACUGGCUCAACAUGAG 470 3243 GCCAGCCACAGAGCAAAAG 181 3243 GCCAGCCACAGAGCAAAAG 181 3261 CUUUUGCUCUGUGGCUGGC 471 3261 GAGGGUUUAUUUUCAGUCC 182 3261 GAGGGUUUAUUUUCAGUCC 182 3279 GGACUGAAAAUAAACCCUC 472 3279 CCCUCUCUCUGGGUCAGAA 183 3279 CCCUCUCUCUGGGUCAGAA 183 3297 UUCUGACCCAGAGAGAGGG 473 3297 ACCAGAGGGCAUGCUGAAU 184 3297 ACCAGAGGGCAUGCUGAAU 184 3315 AUUCAGCAUGCCCUCUGGU 474 3315 UGCCCCCUGCUUACUUGGU 185 3315 UGCCCCCUGCUUACUUGGU 185 3333 ACCAAGUAAGCAGGGGGCA 475 3333 UGAGGGUGCCCCGCCUGAG 186 3333 UGAGGGUGCCCCGCCUGAG 186 3351 CUCAGGCGGGGCACCCUCA 476 3351 GUCAGUGCUCUCAGCUGGC 187 3351 GUCAGUGCUCUCAGCUGGC 187 3369 GCCAGCUGAGAGGACUGAC 477 3369 CAGUGCAAUGCUUGUAGAA 188 3369 CAGUGCAAUGCUUGUAGAA 188 3387 UUCUACAAGCAUUGCACUG 478 3387 AGUAGGAGGAAACAGUUCU 189 3387 AGUAGGAGGAAACAGUUCU 189 3405 AGAACUGUUUCCUCCUACU 479 3405 UCACUGGGAAGAAGCAAGG 190 3405 UCACUGGGAAGAAGCAAGG 190 3423 CCUUGCUUCUUCCCAGUGA 480 3423 GGCAAGAACCCAAGUGCCU 191 3423 GGCAAGAACCCAAGUGCCU 191 3441 AGGCACUUGGGUUCUUGCC 481 3441 UCACCUCGAAAGGAGGCCC 192 3441 UCACCUCGAAAGGAGGCCC 192 3459 GGGCCUCCUUUCGAGGUGA 482 3459 CUGUUCCCUGGAGUCAGGG 193 3459 CUGUUCCCUGGAGUCAGGG 193 3477 CCCUGACUCCAGGGAACAG 483 3477 GUGAACUGCAAAGCUUUGG 194 3477 GUGAACUGCAAAGCUUUGG 194 3495 CCAAAGCUUUGCAGUUCAC 484 3495 GCUGAGACCUGGGAUUUGA 195 3495 GCUGAGACCUGGGAUUUGA 195 3513 UCAAAUCCCAGGUCUCAGC 485 3513 AGAUACCACAAACCCUGCU 196 3513 AGAUACCACAAACCCUGCU 196 3531 AGCAGGGUUUGUGGUAUCU 486 3531 UGAACACAGUGUCUGUUCA 197 3531 UGAACACAGUGUCUGUUCA 197 3549 UGAACAGACACUGUGUUCA 487 3549 AGCAAACUAACCAGCAUUC 198 3549 AGCAAACUAACCAGCAUUC 198 3567 GAAUGCUGGUUAGUUUGCU 488 3567 CCCUACAGCCUAGGGCAGA 199 3567 CCCUACAGCCUAGGGCAGA 199 3585 UCUGCCCUAGGCUGUAGGG 489 3585 ACAAUAGUAUAGAAGUCUG 200 3585 ACAAUAGUAUAGAAGUCUG 200 3603 CAGACUUCUAUACUAUUGU 490 3603 GGAAAAAAACAAAAACAGA 201 3603 GGAAAAAAACAAAAACAGA 201 3621 UCUGUUUUUGUUUUUUUCC 491 3621 AAUUUGAGAACCUUGGACC 202 3621 AAUUUGAGAACCUUGGACC 202 3639 GGUCCAAGGUUCUCAAAUU 492 3639 CACUCCUGUCCCUGUAGCU 203 3639 CACUCCUGUCCCUGUAGCU 203 3657 AGCUACAGGGACAGGAGUG 493 3657 UCAGUCAUCAAAGCAGAAG 204 3657 UCAGUCAUCAAAGCAGAAG 204 3675 CUUCUGCUUUGAUGACUGA 494 3675 GUCUGGCUUUGCUCUAUUA 205 3675 GUCUGGCUUUGCUCUAUUA 205 3693 UAAUAGAGCAAAGCCAGAC 495 3693 AAGAUUGGAAAUGUACACU 206 3693 AAGAUUGGAAAUGUACACU 206 3711 AGUGUACAUUUCCAAUCUU 496 3711 UACCAAACACUCAGUCCAC 207 3711 UACCAAACACUCAGUCCAC 207 3729 GUGGACUGAGUGUUUGGUA 497 3729 CUGUUGAGCCCCAGUGCUG 208 3729 CUGUUGAGCCCCAGUGCUG 208 3747 CAGCACUGGGGCUCAACAG 498 3747 GGAAGGGAGGAAGGCCUUU 209 3747 GGAAGGGAGGAAGGCCUUU 209 3765 AAAGGCCUUCCUCCCUUCC 499 3765 UCUUCUGUGUUAAUUGCGU 210 3765 UCUUCUGUGUUAAUUGCGU 210 3783 ACGCAAUUAACACAGAAGA 500 3783 UAGAGGCUACAGGGGUUAG 211 3783 UAGAGGCUACAGGGGUUAG 211 3801 CUAACCCCUGUAGCCUCUA 501 3801 GCCUGGACUAAAGGCAUCC 212 3801 GCCUGGACUAAAGGCAUCC 212 3819 GGAUGCCUUUAGUCCAGGC 502 3819 CUUGUCUUUUGAGCUAUUC 213 3819 CUUGUCUUUUGAGCUAUUC 213 3837 GAAUAGCUCAAAAGACAAG 503 3837 CACCUCAGUAGAAAAGGAU 214 3837 CACCUCAGUAGAAAAGGAU 214 3855 AUCCUUUUCUACUGAGGUG 504 3855 UCUAAGGGAAGAUCACUGU 215 3855 UCUAAGGGAAGAUCACUGU 215 3873 ACAGUGAUCUUCCCUUAGA 505 3873 UAGUUUAGUUCUGUUGACC 216 3873 UAGUUUAGUUCUGUUGACC 216 3891 GGUCAACAGAACUAAACUA 506 3891 CUGUGCACCUACCCCUUGG 217 3891 CUGUGCACCUACCCCUUGG 217 3909 CCAAGGGGUAGGUGCACAG 507 3909 GAAAUGUCUGCUGGUAUUU 218 3909 GAAAUGUCUGCUGGUAUUU 218 3927 AAAUACCAGCAGACAUUUC 508 3927 UCUAAUUCCACAGGUCAUC 219 3927 UCUAAUUCCACAGGUCAUC 219 3945 GAUGACCUGUGGAAUUAGA 509 3945 CAGAUGCCUGCUUGAUAAU 220 3945 CAGAUGCCUGCUUGAUAAU 220 3963 AUUAUCAAGCAGGCAUCUG 510 3963 UAUAUAAACAAUAAAAACA 221 3963 UAUAUAAACAAUAAAAACA 221 3981 UGUUUUUAUUGUUUAUAUA 511 3981 AACUUUCACUUCUUCCUAU 222 3981 AACUUUCACUUCUUCCUAU 222 3999 AUAGGAAGAAGUGAAAGUU 512 3999 UUGUAAUCGUGUGCCAUGG 223 3999 UUGUAAUCGUGUGCCAUGG 223 4017 CCAUGGCACACGAUUACAA 513 4017 GAUCUGAUCUGUACCAUGA 224 4017 GAUCUGAUCUGUACCAUGA 224 4035 UCAUGGUACAGAUCAGAUC 514 4035 ACCCUACAUAAGGCUGGAU 225 4035 ACCCUACAUAAGGCUGGAU 225 4053 AUCCAGCCUUAUGUAGGGU 515 4053 UGGCACCUCAGGCUGAGGG 226 4053 UGGCACCUCAGGCUGAGGG 226 4071 CCCUCAGCCUGAGGUGCCA 516 4071 GCCCCAAUGUAUGUGUGGC 227 4071 GCCCCAAUGUAUGUGUGGC 227 4089 GCCACACAUACAUUGGGGC 517 4089 CUGUGGGUGUGGGUGGGAG 228 4089 CUGUGGGUGUGGGUGGGAG 228 4107 CUCCCACCCACACCCACAG 518 4107 GUGUGUCUGCUGAGUAAGG 229 4107 GUGUGUCUGCUGAGUAAGG 229 4125 CCUUACUCAGCAGACACAC 519 4125 GAACACGAUUUUCAAGAUU 230 4125 GAACACGAUUUUCAAGAUU 230 4143 AAUCUUGAAAAUCGUGUUC 520 4143 UCUAAAGCUCAAUUCAAGU 231 4143 UCUAAAGCUCAAUUCAAGU 231 4161 ACUUGAAUUGAGCUUUAGA 521 4161 UGACACAUUAAUGAUAAAC 232 4161 UGACACAUUAAUGAUAAAC 232 4179 GUUUAUCAUUAAUGUGUCA 522 4179 CUCAGAUCUGAUCAAGAGU 233 4179 CUCAGAUCUGAUCAAGAGU 233 4197 ACUCUUGAUCAGAUCUGAG 523 4197 UCCGGAUUUCUAACAGUCC 234 4197 UCCGGAUUUCUAACAGUCC 234 4215 GGACUGUUAGAAAUCCGGA 524 4215 CCUGCUUUGGGGGGUGUGC 235 4215 CCUGCUUUGGGGGGUGUGC 235 4233 GCACACCCCCCAAAGCAGG 525 4233 CUGACAACUUAGCUCAGGU 236 4233 CUGACAACUUAGCUCAGGU 236 4251 ACCUGAGCUAAGUUGUCAG 526 4251 UGCCUUACAUCUUUUCUAA 237 4251 UGCCUUACAUCUUUUCUAA 237 4269 UUAGAAAAGAUGUAAGGCA 527 4269 AUCACAGUGUUGCAUAUGA 238 4269 AUCACAGUGUUGCAUAUGA 238 4287 UCAUAUGCAACACUGUGAU 528 4287 AGGCUGCCCUCACUCCCUC 239 4287 AGCCUGCCCUCACUCCCUC 239 4305 GAGGGAGUGAGGGCAGGCU 529 4305 CUGCAGAAUCCCUUUGCAC 240 4305 CUGCAGAAUCCCUUUGCAC 240 4323 GUGCAAAGGGAUUCUGCAG 530 4323 CCUGAGACCCUACUGAAGU 241 4323 CCUGAGACCCUACUGAAGU 241 4341 ACUUCAGUAGGGUCUCAGG 531 4341 UGGCUGGUAGAAAAAGGGG 242 4341 UGGCUGGUAGAAAAAGGGG 242 4359 CCCCUUUUUCUACCAGCCA 532 4359 GCCUGAGUGGAGGAUUAUC 243 4359 GCCUGAGUGGAGGAUUAUC 243 4377 GAUAAUCCUCCACUCAGGC 533 4377 CAGUAUCACGAUUUGCAGG 244 4377 CAGUAUCACGAUUUGCAGG 244 4395 CCUGCAAAUCGUGAUACUG 534 4395 GAUUCCCUUCUGGGCUUCA 245 4395 GAUUCCCUUCUGGGCUUCA 245 4413 UGAAGCCCAGAAGGGAAUC 535 4413 AUUCUGGAAACUUUUGUUA 246 4413 AUUCUGGAAACUUUUGUUA 246 4431 UAACAAAAGUUUCCAGAAU 536 4431 AGGGCUGCUUUUCUUAAGU 247 4431 AGGGCUGCUUUUCUUAAGU 247 4449 ACUUAAGAAAAGCAGCCCU 537 4449 UGCCCACAUUUGAUGGAGG 248 4449 UGCCCAGAUUUGAUGGAGG 248 4467 CCUCCAUCAAAUGUGGGCA 538 4467 GGUGGAAAUAAUUUGAAUG 249 4467 GGUGGAAAUAAUUUGAAUG 249 4485 CAUUCAAAUUAUUUCCACC 539 4485 GUAUUUGAUUUAUAAGUUU 250 4485 GUAUUUGAUUUAUAAGUUU 250 4503 AAACUUAUAAAUCAAAUAC 540 4503 UUUUUUUUUUUUUGGGUUA 251 4503 UUUUUUUUUUUUUGGGUUA 251 4521 UAACCCAAAAAAAAAAAAA 541 4521 AAAAGAUGGUUGUAGCAUU 252 4521 AAAAGAUGGUUGUAGCAUU 252 4539 AAUGCUACAACCAUCUUUU 542 4539 UUAAAAUGGAAAAUUUUCU 253 4539 UUAAAAUGGAAAAUUUUCU 253 4557 AGAAAAUUUUCCAUUUUAA 543 4557 UCCUUGGUUUGCUAGUAUC 254 4557 UCCUUGGUUUGCUAGUAUC 254 4575 GAUACUAGCAAACCAAGGA 544 4575 CUUGGGUGUAUUCUCUGUA 255 4575 CUUGGGUGUAUUCUCUGUA 255 4593 UACAGAGAAUACACCCAAG 545 4593 AAGUGUAGCUCAAAUAGGU 256 4593 AAGUGUAGCUCAAAUAGGU 256 4611 ACCUAUUUGAGCUACACUU 546 4611 UCAUCAUGAAAGGUUAAAA 257 4611 UCAUCAUGAAAGGUUAAAA 257 4629 UUUUAACCUUUCAUGAUGA 547 4629 AAAGCGAGGUGGCCAUGUU 258 4629 AAAGCGAGGUGGCCAUGUU 258 4647 AACAUGGCCACCUCGCUUU 548 4647 UAUGCUGGUGGUUAAGGCC 259 4647 UAUGCUGGUGGUUAAGGCC 259 4665 GGCCUUAACCACCAGCAUA 549 4665 CAGGGCCUCUCCAACCACU 260 4665 GAGGGCCUCUCCAACCACU 260 4683 AGUGGUUGGAGAGGCCCUG 550 4683 UGUGCCACUGACUUGCUGU 261 4683 UGUGCCACUGACUUGCUGU 261 4701 ACAGCAAGUCAGUGGCACA 551 4701 UGUGACCCUGGGCAAGUCA 262 4701 UGUGACGGUGGGCAAGUCA 262 4719 UGACUUGCCCAGGGUCACA 552 4719 ACUUAACUAUAAGGUGCCU 263 4719 ACUUAACUAUAAGGUGCCU 263 4737 AGGCACCUUAUAGUUAAGU 553 4737 UCAGUUUUCCUUCUGUUAA 264 4737 UCAGUUUUCCUUCUGUUAA 264 4755 UUAACAGAAGGAAAACUGA 554 4755 AAAUGGGGAUAAUAAUACU 265 4755 AAAUGGGGAUAAUAAUACU 265 4773 AGUAUUAUUAUCCCCAUUU 555 4773 UGACCUACCUCAAAGGGCA 266 4773 UGACCUACCUCAAAGGGCA 266 4791 UGCCCUUUGAGGUAGGUCA 556 4791 AGUUUUGAGGCAUGACUAA 267 4791 AGUUUUGAGGCAUGACUAA 267 4809 UUAGUCAUGCCUCAAAACU 557 4809 AUGCUUUUUAGAAAGCAUU 268 4809 AUGCUUUUUAGAAAGCAUU 268 4827 AAUGCUUUCUAAAAAGCAU 558 4827 UUUGGGAUCCUUCAGCACA 269 4827 UUUGGGAUCCUUCAGCACA 269 4845 UGUGCUGAAGGAUCCCAAA 559 4845 AGGAAUUCUCAAGACCUGA 270 4845 AGGAAUUCUCAAGACCUGA 270 4863 UCAGGUCUUGAGAAUUCCU 560 4863 AGUAUUUUUUAUAAUAGGA 271 4863 AGUAUUUUUUAUAAUAGGA 271 4881 UCCUAUUAUAAAAAAUACU 561 4881 AAUGUCCACCAUGAACUUG 272 4881 AAUGUCCACCAUGAACUUG 272 4899 CAAGUUCAUGGUGGACAUU 562 4899 GAUACGUCCGUGUGUCCCA 273 4899 GAUACGUCCGUGUGUCCCA 273 4917 UGGGACACACGGACGUAUC 563 4917 AGAUGCUGUCAUUAGUCUA 274 4917 AGAUGCUGUCAUUAGUCUA 274 4935 UAGACUAAUGACAGCAUCU 564 4935 AUAUGGUUCUCCAAGAAAC 275 4935 AUAUGGUUCUCCAAGAAAC 275 4953 GUUUCUUGGAGAACCAUAU 565 4953 CUGAAUGAAUCCAUUGGAG 276 4953 CUGAAUGAAUCCAUUGGAG 276 4971 CUCCAAUGGAUUCAUUCAG 566 4971 GAAGCGGUGGAUAACUAGC 277 4971 GAAGCGGUGGAUAACUAGC 277 4989 GCUAGUUAUCCACCGCUUC 567 4989 CCAGACAAAAUUUGAGAAU 278 4989 CCAGAGAAAAUUUGAGAAU 278 5007 AUUCUCAAAUUUUGUCUGG 568 5007 UACAUAAACAACGCAUUGC 279 5007 UACAUAAACAACGCAUUGC 279 5025 GGAAUGCGUUGUUUAUGUA 569 5025 CCACGGAAACAUACAGAGG 280 5025 CCACGGAAACAUACAGAGG 280 5043 CCUCUGUAUGUUUCCGUGG 570 5043 GAUGCCUUUUCUGUGAUUG 281 5043 GAUGCCUUUUCUGUGAUUG 281 5061 CAAUCACAGAAAAGGCAUC 571 5061 GGGUGGGAUUUUUUCCCUU 282 5061 GGGUGGGAUUUUUUCCCUU 282 5079 AAGGGAAAAAAUCCCACCC 572 5079 UUUUAUGUGGGAUAUAGUA 283 5079 UUUUAUGUGGGAUAUAGUA 283 5097 UACUAUAUCCCACAUAAAA 573 5097 AGUUACUUGUGACAAAAAU 284 5097 AGUUACUUGUGACAAAAAU 284 5115 AUUUUUGUCACAAGUAACU 574 5115 UAAUUUUGGAAUAAUUUCU 285 5115 UAAUUUUGGAAUAAUUUCU 285 5133 AGAAAUUAUUCCAAAAUUA 575 5133 UAUUAAUAUCAACUCUGAA 286 5133 UAUUAAUAUCAACUCUGAA 286 5151 UUCAGAGUUGAUAUUAAUA 576 5151 AGCUAAUUGUACUAAUCUG 287 5151 AGCUAAUUGUACUAAUCUG 287 5169 CAGAUUAGUACAAUUAGCU 577 5169 GAGAUUGUGUUUGUUCAUA 288 5169 GAGAUUGUGUUUGUUCAUA 288 5187 UAUGAACAAACACAAUCUC 578 5187 AAUAAAAGUGAAGUGAAUC 289 5187 AAUAAAAGUGAAGUGAAUC 289 5205 GAUUCACUYCACUUUUAUU 579 5201 GAAUCUAAAAAAAAAAAAA 290 5201 GAAUCUAAAAAAAAAAAAA 290 5219 UUUUUUUUUUUUUAGAUUC 580

The 3′-ends of the Upper sequence and the Lower sequence of the siNA construct can include an overhang sequence, for example about 1, 2, 3, or 4 nucleotides in length, preferably 2 nucleotides in length, wherein the overhanging sequence of the lower sequence is optionally complementary to a portion of the target sequence. The upper sequence is also referred to as the sense strand, whereas the lower sequence is also referred to as the antisense strand. The upper and lower sequences in the Table can further comprise a chemical modification having Formulae I-VII, such as exemplary siNA constructs shown in FIGS. 4 and 5, or having modifications described in Table IV or any combination thereof.

TABLE III SCD Synthetic Modified siNA Constructs Target Seq Seq Pos Target ID Cmpd# Aliases Sequence ID  993 GAUAUGCUGUGGUGCUUAAUGCC 581 31021 SCD: 995U21 sense siNA UAUGCUGUGGUGCUUAAUGTT 597 2518 ACUGCUGGACAUGAGAUGGAGAG 582 31022 SCD: 2520U21 sense siNA UGCUGGACAUGAGAUGGAGTT 598 3783 UAGAGGCUACAGGGGUUAGCCUG 583 31023 SCD: 3785U21 sense siNA GAGGCUACAGGGGUUAGCCTT 599 4772 CUGACCUACCUCAAAGGGCAGUU 584 31024 SCD: 4774U21 sense siNA GACCUACCUCAAAGGGCAGTT 600  660 ACACAAUGGCAUUCCAGAAUGAU 585 31635 SCD: 662U21 sense siNA ACAAUGGCAUUCCAGAAUGTT 601 2879 UGUCUGUCCCUUUUCUUUGACCA 586 31636 SCD: 2881U21 sense siNA UCUGUCCCUUUUCUUUGACTT 602 3557 AACCAGCAUUCCCUACAGCCUAG 587 31637 SCD: 3559U21 sense siNA CCAGCAUUCCCUACAGCCUTT 603 4970 AGAAGCGGUGGAUAACUAGCCAG 588 31638 SCD: 4972U21 sense siNA AAGCGGUGGAUAACUAGCCTT 604  993 GAUAUGCUGUGGUGCUUAAUGCC 581 31097 SCD: 1013L21 antisense siNA CAUUAAGCACCACAGCAUATT 605 (995C) 2518 ACUGCUGGACAUGAGAUGGAGAG 582 31098 SCD: 2538L21 antisense siNA CUCCAUCUCAUGUCCAGCATT 606 (2520C) 3783 UAGAGGCUACAGGGGUUAGCCUG 583 31099 SCD: 3803L21 antisense siNA GGCUAACCCCUGUAGCCUCTT 607 (3785C) 4772 CUGACCUACCUCAAAGGGCAGUU 584 31100 SCC: 4792L21 antisense siNA CUGCCCUUUGAGGUAGGUCTT 608 (4774C)  660 ACACAAUGGCAUUCCAGAAUGAU 585 31639 SCD: 680L21 antisense siNA CAUUCUGGAAUGCCAUUGUTT 609 (662C) 2879 UGUCUGUCCCUUUUCUUUGACCA 586 31640 SCD: 2899L21 antisense siNA GUCAAAGAAAAGGGACAGATT 610 (2881C) 3557 AACCAGCAUUCCCUACAGCCUAG 587 31641 SCD: 3577L21 antisense siNA AGGCUGUAGGGAAUGCUGGTT 611 (3559C) 4970 AGAAGCGGUGGAUAACUAGCCAG 588 31642 SCD: 4990L21 antisense siNA GGCUAGUUAUCCACCGCUUTT 612 (4972C)  993 GAUAUG0UGUGGUGCUUAAUGCC 581 30873 SCD: 995U21 sense siNA stab04 B uAuGcuGuGGuGcuuAAuGTT B 613 2518 ACUGCUGGACAUGAGAUGGAGAG 582 30874 SCD: 2520U21 sense siNA stab04 B uGcuGGAcAuGAGAuGGAGTT B 614 3783 UAGAGGCUACAGGGGUUAGCCUG 583 30875 SCD: 3785U21 sense siNA stab04 B GAGGouAcAGGGGuuAGccTT B 615 4772 CUGACCUACCUCAAAGGGCAGUU 584 30876 SCD: 4774U21 sense siNA stab04 B GAccuAccucAAAGGGcAGTT B 616  660 ACACAAUGGCAUUCCAGAAUGAU 585 SCD: 662U21 sense siNA stab04 B AcAAuGGcAuuccAGAAuGTT B 617 2879 UGU0UGU000UUUUCUUUGACCA 586 SCD: 2881U21 sense siNA stab04 B ucuGucccuuuucuuuGAcTT B 618 3557 AACCAGCAUUCCCUACAGCCUAG 587 SCD: 3559U21 sense siNA stab04 B ccAGcAuucccuAcAGccuTT B 619 4970 AGAAG0GGUGGAUAACUAGCCAG 588 SCD: 4972U21 sense siNA stab04 B AAGcGGuGGAuAAcuAGccTT B 620  993 GAUAUGCUGUGGUGCUUAAUGCC 581 30877 SCD: 1013L21 antisense siNA cAuuAAGcAccAcAGcAuATsT 621 (995C) stab05 2518 ACUGCUGGACAUGAGAUGGAGAG 582 30878 SCD: 2538L21 antisense siNA cuccAucucAuGuccAGcATsT 622 (2520C) stab05 3783 UAGAGGCUACAGGGGUUAGCCUG 583 30879 SCD: 3803L21 antisense siNA GGcuAAccccuGuAGccucTsT 623 (3785C) stab05 4772 CUGACCUACCUCAAAGGGCAGUU 584 30880 SCD: 4792L21 antisense siNA cuGcccuuuGAGGuAGGucTsT 624 (4774C) stab05  660 ACACAAUGGCAUU0CAGAAUGAU 585 SCD: 680L21 antisense siNA cAuucuGGAAuGccAuuGuTsT 625 (662C) stab05 2879 UGUCUGUCCCUUUUCUUUGACCA 586 SCD: 2899L21 antisense siNA GucAAAGAAAAGGGAcAGATsT 626 (2881C) stab05 3557 AACCAGCAUUCCCUACAGCCUAG 587 SCD: 3577L21 antisense siNA AGGcuGuAGGGAAuGcuGGTsT 627 (3559C) stab05 4970 AGAAGCGGUGGAUAACUAGCCAG 588 SCD: 4990L21 antisense siNA GGcuAGuuAuccAccGcuuTsT 628 (4972C) stab05  993 GAUAUGCUGUGGUGCUUAAUGCC 581 SCD: 995U21 sense siNA stab07 B uAuGcuGuGGuGcuuAAuGTT B 629 2518 ACUGCUGGACAUGAGAUGGAGAG 582 SCD: 2520U21 sense siNA stab07 B uGcuGGAcAuGAGAuGGAGTT B 630 3783 UAGAGGCUACAGGGGUUAGCCUG 583 SCD: 3785U21 sense siNA stab07 B GAGGcuAcAGGGCuuAGccTT B 631 4772 CUGACCUACCUCAAAGGGCAGUU 584 SCD: 4774U21 sense siNA stab07 B GAccuAccucAAAGGGcAGTT B 632  660 ACACAAUGGCAUUCCAGAAUGAU 585 SCD: 662U21 sense siNA stab07 B AcAAuGGcAuuccAGAAuGTT B 633 2879 UGUCUGUCCCUUUUCUUUGACCA 586 SCD: 2881U21 sense siNA stab07 B ucuGucccuuuucuuuGAcTT B 634 3557 AACCAGCAUUCCCUACAGCCUAG 587 31871 SCD: 3559U21 sense siNA stab07 B ccAGcAuucccuAcAGccuTT B 635 4970 AGAAGCGGUGGAUAACUAGCCAG 588 SCD: 4972U21 sense siNA stab07 B AAGcGGuGGAuAAcuAGccTT B 636  993 GAUAUGCUGUGGUGCUUAAUGCC 581 SCD: 1013L21 antisense siNA cAuuAAGcAccAcAGcAuATsT 637 (995C) stab11 2518 ACUGCUGGACAUGAGAUGGAGAG 582 SCD: 2538L21 antisense siNA cuccAucucAuGuccAGcATsT 638 (2520C) stab11 3783 UAGAGGCUACAGGGGUUAGCCUG 583 SCD: 3803L21 antisense siNA GGcuAAccccuGuAGccucTsT 639 (3785C) stab11 4772 CUGACCUACCUCAAAGGGCAGUU 584 SCD: 4792L21 antisense siNA cuGcccuuuGAGGuAGGucTsT 640 (4774C) stab11  660 ACACAAUGGCAUUCCAGAAUGAU 585 SCD: 680L21 antisense siNA cAuucuGGAAuGccAuuGuTsT 641 (662C) stab11 2879 UGUCUGUCCCUUUUCUUUGACCA 586 SCD: 2899L21 antisense siNA GucAAAGAAAAGGGAcAGATsT 642 (2881C) stab11 3557 AACCAGCAUUCCCUACAGCCUAG 587 SCD: 3577L21 antisense siNA AGGcuGuAGGGAAuGcuGGTsT 643 (3559C) stab11 4970 AGAAGCGGUGGAUAACUAGCCAG 588 SCD: 4990L21 antisense siNA GGcuAGuuAuccAccGcuuTsT 644 (4972C) stab11  993 GAUAUGCUGUGGUGCUUAAUGCC 581 SCD: 995U21 sense siNA stab18 B uAuGcuGuGGuGcuuAAuGTT B 645 2518 ACUGCUGGACAUGAGAUGGAGAG 582 SCD: 2520U21 sense siNA stab18 B uGcuGGAcAuGAGAuGGAGTT B 646 3783 UAGAGGCUACAGGGGUUAGCCUG 583 SCD: 3785U21 sense siNA stab18 B GAGGcuAcAGGGGuuAGccTT B 647 4772 CUGACCUACCUCAAAGGGCAGUU 584 SCD: 4774U21 sense siNA stab18 B GAccuAccucAAAGGGcAGTT B 648  660 ACACAAUGGCAUUCCAGAAUGAU 585 SCD: 662U21 sense siNA stab18 B AcAAuGGcAuuccAGAAuGTT B 649 2879 UGUCUGUCCCUUUUCUUUGACCA 586 SCD: 2881U21 sense siNA stab18 B ucuGucccuuuucuuuGAcTT B 650 3557 AACCAGCAUUCCCUACAGCCUAG 587 SCD: 3559U21 sense siNA stab18 B ccAGcAuucccuAcAGccuTT B 651 4970 AGAAGCGGUGGAUAACUAGCCAG 588 SCD: 4972U21 sense siNA stab18 B AAGcGGuGGAuAAouAGccTT B 652  993 GAUAUGCUGUGGUGCUUAAUGCC 581 SCD: 1013L21 antisense siNA cAuuAAGcAccAcAGcAuATsT 653 (995C) stab08 2518 ACUGCUGGACAUGAGAUGGAGAG 582 SCD: 2538L21 antisense siNA cuccAucucAuGuccAGcATsT 654 (2520C) stab08 3783 UAGAGGCUACAGGGGUUAGCCUG 583 SCD: 3803L21 antisense siNA GGcuAAccccuGuAGccucTsT 655 (3785C) stab08 4772 CUGACCUACCUCAAAGGGCAGUU 584 SCD: 4792L21 antisense siNA cuGcccuuuGAGGuAGGucTsT 656 (4774C) stab08  660 ACACAAUGGCAUUCCAGAAUGAU 585 SCD: 680L21 antisense siNA cAuucuGGAAuGccAuuGuTsT 657 (662C) stab08 2879 UGUCUGUCCCUUUUCUUUGACCA 586 SCD :2899L21 antisense siNA GucAAAGAAAAGGGAcAGATsT 658 (2881C) stab08 3557 AACCAGCAUUCCCUACAGCCUAG 587 31877 SCD: 3577L21 antisense siNA AGGcuGuAGGGAAuGcuGGTsT 659 (3559C) stab08 4970 AGAAGCGGUGGAUAACUAGCCAG 588 SCD: 4990L21 antisense siNA GGcuAGuuAuccAccGcuuTsT 660 (4972C) stab08  993 GAUAUGCUGUGGUGCUUAAUGCC 581 SCD: 995U21 sense siNA stab09 B UAUGCUGUGGUGCUUAAUGTT B 661 2518 ACUGCUGGACAUGAGAUGGAGAG 582 SCD: 2520U21 sense siNA stab09 B UGCUGGACAUGAGAUGGAGTT B 662 3783 UAGAGGCUACAGGGGUUAGCCUG 583 SCD: 3785U21 sense siNA stab09 B GAGGCUACAGGGGUUAGCCTT B 663 4772 CUGACCUACCUCAAAGGGCAGUU 584 SCD: 4774U21 sense siNA stab09 B GACCUACCUCAAAGGGCAGTT B 664  660 ACACAAUGGCAUUCCAGAAUGAU 585 SCD: 662U21 sense siNA stab09 B ACAAUGGCAUUCCAGAAUGTT B 665 2879 UGUCUGUCCCUUUUCUUUGACCA 586 SCC: 2881U21 sense siNA stab09 B UCUGUCCCUUUUCUUUGACTT B 666 3557 AACCAGCAUUCCCUACAGCCUAG 587 SCD: 3559U21 sense siNA stab09 B CCAGCAUUCCCUACAGCCUTT B 667 4970 AGAAGCGGUGGAUAACUAGCCAG 588 SCD: 4972U21 sense siNA stab09 B AAGCGGUGGAUAACUAGCCTT B 668  993 GAUAUGCUGUGGUGCUUAAUGCC 581 SCD: 1013L21 antisense siNA CAUUAAGCACCACAGCAUATsT 669 (995C) stab10 2518 ACUGCUGGACAUGAGAUGGAGAG 582 SCD: 2538L21 antisense siNA CUCCAUCUCAUGUCCAGCATsT 670 (2520C) stab10 3783 UAGAGGCUACAGGGGUUAGCCUG 583 SCD: 3803L21 antisense siNA GGCUAACCCCUGUAGCCUCTsT 671 (3785C) stab10 4772 CUGACCUACCUCAAAGGGCAGUU 584 SCD: 4792L21 antisense siNA CUGCCCUUUGAGGUAGGUCTsT 672 (4774C) stab10  660 ACACAAUGGCAUUCCAGAAUGAU 585 SCD: 680L21 antisense siNA CAUUCUGGAAUGCCAUUGUTsT 673 (662C) stab10 2879 UGUCUGUCCCUUUUCUUUGACCA 586 SCD: 2899L21 antisense siNA GUCAAAGAAAAGGGACAGATsT 674 (2881C) stab10 3557 AACCAGCAUUCCCUACAGCCUAG 587 SCD: 3577L21 antisense siNA AGGCUGUAGGGAAUGCUGGTsT 675 (3559C) stab10 4970 AGAAGCGGUGGAUAACUAGCCAG 588 SCD: 4990L21 antisense siNA GGCUAGUUAUCCACCGCUUTsT 676 (4972C) stab10  993 GAUAUGCUGUGGUGCUUAAUGCC 581 SCD: 1013L21 antisense siNA cAuuAAGcAccAcAGcAuATT B 677 (995C) stab19 2518 ACUGCUGGACAUGAGAUGGAGAG 582 SCD: 2538L21 antisense siNA cuccAucucAuGuccAGcATT B 678 (2520C) stab19 3783 UAGAGGCUACAGGGGUUAGCCUG 583 SCD: 3803L21 antisense siNA GGcuAAccccuGuAGccucTT B 679 (3785C) stab19 4772 CUGACCUACCUCAAAGGGCAGUU 584 SCD: 4792L21 antisense siNA cuGcccuuuGAGGuAGGucTT B 680 (4774C) stab19  660 ACACAAUGGCAUUCCAGAAUGAU 585 SCD: 680L21 antisense siNA cAuucuGGAAuGccAuuGuTT B 681 (662C) stab19 2879 UGUCUGUCCCUUUUCUUUGACCA 586 SCD: 2899L21 antisense siNA GucAAAGAAAAGGGAcAGATT B 682 (2881C) stab19 3557 AACCAGCAUUCCCUACAGCCUAG 587 SCD: 3577L21 antisense siNA AGGcuGuAGGGAAuGcuGGTT B 683 (3559C) stab19 4970 AGAAGCGGUGGAUAACUAGCCAG 588 SCD: 4990L21 antisense siNA GGcuAGuuAuccAccGcuuTT B 684 (4972C) stab19  993 GAUAUGCUGUGGUGCUUAAUGCC 581 SCD: 1013121 antisense siNA CAUUAAGCACCACAGCAUATT B 685 (995C) stab22 2518 ACUGCUGGACAUGAGAUGGAGAG 582 SCD: 2538L21 antisense siNA CUCCAUCUCAUGUCCAGCATT B 686 (2520C) stab22 3783 UAGAGGCUACAGGGGUUAGCCUG 583 SCD: 3803L21 antisense siNA GGCUAACCCCUGUAGCCUCTT B 687 (3785C) stab22 4772 CUGACCUACCUCAAAGGGCAGUU 584 SCD: 4792L21 antisense siNA CUGCCCUUUGAGGUAGGUCTT B 688 (4774C) stab22  660 ACACAAUGGCAUUCCAGAAUGAU 585 SCD: 680L21 antisense siNA CAUUCUGGAAUGCCAUUGUTT B 689 (662C) stab22 2879 UGUCUGUCCCUUUUCUUUGACCA 586 SCD: 2899L21 anUsense siNA GUCAAAGAAAAGGGACAGATT B 690 (2881C) stab22 3557 AACCAGCAUUCCCUACAGCCUAG 587 SCD: 3577L21 antisense siNA AGGCUGUAGGGAAUGCUGGTT B 691 (3559C) stab22 4970 AGAAGCGGUGGAUAACUAGCCAG 588 SCD: 4990L21 antisense siNA GGCUAGUUAUCCACCGCUUTT B 692 (4972C) stab22  645 UUCUGAUCAUUGCCAACACAAUG 589 SCD: 647U21 sense siNA CUGAUCAUUGCCAACACAATT 693 1192 CACCACAUUCUUCAUUGAUUGCA 590 SCD: 1194U21 sense siNA CCACAUUCUUCAUUGAUUGTT 694 2023 GUUUGGCAAUGCUAAUUCAAUGC 591 SCD: 2025U21 sense siNA UUGGCAAUGCUAAUUCAAUTT 695 2728 AGGCUUCUCUCCACAGUGUUGUG 592 SCC: 2730U21 sense siNA GCUUCUCUCCACAGUGUUGTT 696 3554 ACUAACCAGCAUUCCCUACAGCC 593 SCD: 3556U21 sense siNA UAACCAGCAUUCCCUACAGTT 697 4316 CUUUGCACCUGAGACCCUACUGA 594 SCD: 4318U21 sense siNA UUGCACCUGAGACCCUACUTT 698 4318 UUGCACCUGAGACCCUACUGAAG 595 SCD: 4320U21 sense siNA GCACCUGAGACCCUACUGATT 699 4775 ACCUACCUCAAAGGGCAGUUUUG 596 SCD: 4777U21 sense siNA CUACCUCAAAGGGCAGUUUTT 700  645 UUCUGAUCAUUGCCAACACAAUG 589 SCD: 665L21 antisense siNA UUGUGUUGGCAAUGAUCAGTT 701 (647C) 1192 CACCACAUUCUUCAUUGAUUGCA 590 SCD: 1212L21 an˜sense siNA CAAUCAAUGAAGAAUGUGGTT 702 (1194C) 2023 GUUUGGCAAUGCUAAUUCAAUGC 591 SCD: 2043L21 antisense siNA AUUGAAUUAGCAUUGCCAATT 703 (2025C) 2728 AGGCUUCUCUCCACAGUGUUGUG 592 SCD: 2748L21 antisense siNA CAACACUGUGGAGAGAAGCTT 704 (2730C) 3554 ACUAACCAGCAUUCCCUACAGCC 593 SCD: 3574L21 antisense siNA CUGUAGGGAAUGCUGGUUATT 705 (3556C) 4316 CUUUGCACCUGAGACCCUACUGA 594 SCD: 4336L21 antisense siNA AGUAGGGUCUCAGGUGCAATT 706 (4318C) 4318 UUGCACCUGAGACCCUACUGAAG 595 SCD: 4338L21 antisense siNA UCAGUAGGGUCUCAGGUGCTT 707 (4320C) 4775 ACCUACCUCAAAGGGCAGUUUUG 596 SCD: 4795L21 antisense siNA AAACUGCCCUUUGAGGUAGTT 708 (4777C)  645 UUCUGAUCAUUGCCAACACAAUG 589 SCD: 647U21 sense siNA stab04 B cuGAucAuuGccAAcAcAATT B 709 1192 CACCACAUUCUUCAUUGAUUGCA 590 SCD: 1194U21 sense siNA stab04 B ccAcAuucuucAuuGAuuGTT B 710 2023 GUUUGGCAAUGCUAAUUCAAUGC 591 SCD: 2025U21 sense siNA stab04 B uuGGcAAuGcuAAuucAAuTT B 711 2728 AGGCUUCUCUCCACAGUGUUGUG 592 SCD: 2730U21 sense siNA stab04 B GcuucucuccAcAGuGuuGTT B 712 3554 ACUAACCAGCAUUCCCUACAGCC 593 SCD: 3556U21 sense siNA stab04 B uAAccAGcAuucccuAcAGTT B 713 4316 CUUUGCACCUGAGACCCUACUGA 594 SCD: 4318U21 sense siNA stab04 B uuGcAccuGAGAcccuAcuTT B 714 4318 UUGCACCUGAGACCCUACUGAAG 595 SCD: 4320U21 sense siNA stab04 B GcAccuGAGAcccuAcuGATT B 715 4775 ACCUACCUCAAAGGGCAGUUUUG 596 SCD: 4777U21 sense siNA stab04 B cuAccucAAAGGGcAGuuuTT B 716  645 UUCUGAUCAUUGCCAACACAAUG 589 SCD: 665L21 antisense siNA uuGuGuuGGcAAuGAucAGTsT 717 (647C) stab05 1192 CACCACAUUCUUCAUUGAUUGCA 590 SCD: 1212L21 antisense siNA cAAucAAuGAAGAAuGuGGTsT 718 (1194C) stab05 2023 GUUUGGCAAUGCUAAUUCAAUGC 591 SCD: 2043L21 antisense siNA AuuGAAuuAGcAuuGccAATsT 719 (2025C) stab05 2728 AGGCUUCUCUCCACAGUGUUGUG 592 SCD: 2748L21 antisense siNA cAAcAcuGuGGAGAGAAGcTsT 720 (2730C) stab05 3554 ACUAACCAGCAUUCCCUACAGCC 593 SCD: 3574L21 antisense siNA cuGuAGGGAAuGcuGGuuATsT 721 (3556C) stab05 4316 CUUUGCACCUGAGACCCUACUGA 594 SCD: 4336L21 antisense siNA AGuAGGGucucAGGuGcAATsT 722 (4318C) stab05 4318 UUGCACCUGAGACCCUACUGAAG 595 SCD: 4338L21 antisense siNA ucAGuAGGGucucAGGuGcTsT 723 (4320C) stab05 4775 ACCUACCUCAAAGGGCAGUUUUG 596 SCD: 4795L21 antisense siNA AAAcuGcccuuuGAGGuAGTsT 724 (4777C) stab05  645 UUCUGAUCAUUGCCAACACAAUG 589 SCD: 647U21 sense siNA stab07 B cuGAucAuuGccAAcAcAATT B 725 1192 CACCACAUUCUUCAUUGAUUGCA 590 SCD: 1194U21 sense siNA stab07 B ccAcAuucuucAuuGAuuGTT B 726 2023 GUUUGGCAAUGCUAAUUCAAUGC 591 SCD: 2025U21 sense siNA stab07 B uuGGcAAuGcuAAuucAAuTT B 727 2728 AGGCUUCUCUCCACAGUGUUGUG 592 SCD: 2730U21 sense siNA stab07 B GcuucucuccAcAGuGuuGTT B 728 3554 ACUAACCAGCAUUCCCUACAGCC 593 SCC: 3556U21 sense siNA stab07 B uAAccAGcAuucccuAcAGTT B 729 4316 CUUUGCACCUGAGACCCUACUGA 594 SCD: 4318U21 sense siNA stab07 B uuGcAccuGAGAcccuAcuTT B 730 4318 UUGCACCUGAGACCCUACUGAAG 595 SCD: 4320U21 sense siNA stab07 B GcAccuGAGAcccuAcuGATT B 731 4775 ACCUACCUCAAAGGGCAGUUUUG 596 SCD: 4777U21 sense siNA stab07 B cuAccucAAAGGGcAGuuuTT B 732  645 UUCUGAUCAUUGCCAACACAAUG 589 SCD: 665L21 antisense siNA uuGuGUuGGcAAuGAucAGTsT 733 (647C) stab11 1192 CACCACAUUCUUCAUUGAUUGCA 590 SCD: 1212L21 antisense siNA cAAucAAuGAAGAAuGuGGTsT 734 (1194C) stab11 2023 GUUUGGCAAUGCUAAUUCAAUGC 591 SCD: 2043L21 antisense siNA AuuGAAuuAGcAuuGccAATsT 735 (2025C) stab11 2728 AGGCUUCUCUCCACAGUGUUGUG 592 SCD: 2748L21 antisense siNA cAAcAcuGuGGAGAGAAGcTsT 736 (2730C) stab11 3554 ACUAACCAGCAUUCCCUACAGCC 593 SCD: 3574L21 antisense siNA cuGuAGGGAAuGcuGGuuATsT 737 (3556C) stab11 4316 CUUUGCACCUGAGACCCUACUGA 594 SCD: 4336L21 antisense siNA AGuAGGGucucAGGuGcAATsT 738 (4318C) stab11 4318 UUGCACCUGAGACCCUACUGAAG 595 SCD: 4338L21 antisense siNA ucAGuAGGGucucAGGuGcTsT 739 (4320C) stab11 4775 ACCUACCUCAAAGGGCAGUUUUG 596 SCD: 4795L21 antisense siNA AAAcuGcccuuuGAGGuAGTsT 740 (4777C) stab11  645 UUCUGAUCAUUGCCAACACAAUG 589 SCD: 647U21 sense siNA stab18 B cuGAucAuuGccAAcAcAATT B 741 1192 CACCACAUUCUUCAUUGAUUGCA 590 SCD: 1194U21 sense siNA stab18 B ccAcAuucuucAuuGAuuGTT B 742 2023 GUUUGGCAAUGCUAAUUCAAUGC 591 SCD: 2025U21 sense siNA stab18 B uuGGcAAuGcuAAuucAAuTT B 743 2728 AGGCUUCUCUCCACAGUGUUGUG 592 SCD: 2730U21 sense siNA stab18 B GcuucucuccAcAGuGuuGTT B 744 3554 ACUAACCAGCAUUCCCUACAGCC 593 SCD: 3556U21 sense siNA stab18 B uAAccAGcAuucccuAcAGTT B 745 4316 CUUUGCACCUGAGACCCUACUGA 594 SCD: 4318U21 sense siNA stab18 B uuGcAccuGAGAcccuAcuTT B 746 4318 UUGCACCUGAGACCCUACUGAAG 595 SCD: 4320U21 sense siNA stab18 B GcAccuGAGAcccuAcuGATT B 747 4775 ACCUACCUCAAAGGGCAGUUUUG 596 SCD: 4777U21 sense siNA stab18 B cuAccucAAAGGGcAGuuuTT B 748  645 UUCUGAUCAUUGCCAACACAAUG 589 SCD: 665L21 antisense siNA uuGuGuuGGcAAuGAucAGTsT 749 (647C) stab08 1192 CACCACAUUCUUCAUUGAUUGCA 590 SCD: 1212L21 antisense siNA cAAucAAuGAAGAAuGuGGTsT 750 (1194C) stab08 2023 GUUUGGCAAUGCUAAUUCAAUGC 591 SCD: 2043L21 antisense siNA AuuGAAuuAGcAuuGccAATsT 751 (2025C) stab08 2728 AGGCUUCUCUCCACAGUGUUGUG 592 SCD: 2748L21 antisense siNA cAAcAcuGuGGAGAGAAGcTsT 752 (2730C) stab08 3554 ACUAACCAGCAUUCCCUACAGCC 593 SCD: 3574L21 antisense siNA cuGuAGGGAAuGcuGGuuATsT 753 (3556C) stab08 4316 CUUUGCACCUGAGACCCUACUGA 594 SCD: 4336L21 antisense siNA AGuAGGGucucAGGuGcAATsT 754 (4318C) stab08 4318 UUGCACCUGAGACCCUACUGAAG 595 SCD: 4338L21 antisense siNA ucAGuAGGGucucAGGuGcTsT 755 (4320C) stab08 4775 ACCUACCUCAAAGGGCAGUUUUG 596 SCD: 4795L21 antisense siNA AAAcuGcccuuuGAGGuAGTsT 756 (4777C) stab08  645 UUCUGAUCAUUGCCAACACAAUG 589 37108 SCD: 647U21 sense siNA stab09 B CUGAUCAUUGCCAACACAATT B 757 1192 CACCACAUUCUUCAUUGAUUGCA 590 37109 SCD: 1194U21 sense siNA stab09 B CCACAUUCUUCAUUGAUUGTT B 758 2023 GUUUGGCAAUGCUAAUUCAAUGC 591 37110 SCD: 2025U21 sense siNA stab09 B UUGGCAAUGCUAAUUCAAUTT B 759 2728 AGGCUUCUCUCCACAGUGUUGUG 592 37111 SCD: 2730U21 sense siNA stab09 B GCUUCUCUCCACAGUGUUGTT B 760 3554 ACUAACCAGCAUUCCCUACAGCC 593 37112 SCD: 3556U21 sense siNA stab09 B UAACCAGCAUUCCCUACAGTT B 761 4316 CUUUGCACCUGAGACCCUACUGA 594 37113 SCD: 4318U21 sense siNA stab09 B UUGCACCUGAGACCCUACUTT B 762 4318 UUGCACCUGAGACCCUACUGAAG 595 37114 SCD: 4320U21 sense siNA stab09 B GCACCUGAGACCCUACUGATT B 763 4775 ACCUACCUCAAAGGGCAGUUUUG 596 37115 SCD: 4777U21 sense siNA stab09 B CUACCUCAAAGGGCAGUUUTT B 764  645 UUCUGAUCAUUGCCAACACAAUG 589 SCD: 665L21 antisense siNA UUGUGUUGGCAAUGAUCAGTsT 765 (647C) stab10 1192 CACCACAUUCUUCAUUGAUUGCA 590 SCD: 1212L21 antisense siNA CAAUCAAUGAAGAAUGUGGTsT 766 (1194C) stab10 2023 GUUUGGCAAUGCUAAUUCAAUGC 591 SCD: 2043L21 antisense siNA AUUGAAUUAGCAUUGCCAATsT 767 (2025C) stab10 2728 AGGCUUCUCUCCACAGUGUUGUG 592 SCD: 2748L21 antisense siNA CAACACUGUGGAGAGAAGCTsT 768 (2730C) stab10 3554 ACUAACCAGCAUUCCCUACAGCC 593 SCD: 3574L21 antisense siNA CUGUAGGGAAUGCUGGUUATsT 769 (3556C) stab10 4316 CUUUGCACCUGAGACCCUACUGA 594 SCD: 4336L21 antisense siNA AGUAGGGUCUCAGGUGCAATsT 770 (4318C) stab10 4318 UUGCACCUGAGACCCUACUGAAG 595 SCD: 4338L21 antisense siNA UCAGUAGGGUCUCAGGUGCTsT 771 (4320C) stab10 4775 ACCUACCUCAAAGGGCAGUUUUG 596 SCD: 4795L21 anfisense siNA AAACUGCCCUUUGAGGUAGTsT 772 (4777C) stab10 645 UUCUGAUCAUUGCCAACACAAUG 589 SCD: 665L21 antisense siNA uuGuGuuGGcAAuGAucAGTT B 773 (647C) stab19 1192 CACCACAUUCUUCAUUGAUUGCA 590 SCD: 1212L21 antisense siNA cAAucAAuGAAGAAuGuGGTT B 774 (1194C) stab19 2023 GUUUGGCAAUGCUAAUUCAAUGC 591 SCD: 2043L21 antisense siNA AuuGAAuuAGcAuuGccAATT B 775 (2025C) stab19 2728 AGGCUUCUCUCCACAGUGUUGUG 592 SCD: 2748L21 antisense siNA cAAcAcuGuGGAGAGAAGcTT B 776 (2730C) stab19 3554 ACUAACCAGCAUUCCCUACAGCC 593 SCD: 3574L21 antisense siNA cuGuAGGGAAuGcuGGuuATT B 777 (3556C) stab19 4316 CUUUGCACCUGAGACCCUACUGA 594 SCD: 4336L21 antisense siNA AGuAGGGucucAGGuGcAATT B 778 (4318C) stab19 4318 UUGCACCUGAGACCCUACUGAAG 595 SCD: 4338L21 antisense siNA ucAGuAGGGucucAGGuGcTT B 779 (4320C) stab19 4775 ACCUACCUCAAAGGGCAGUUUUG 596 SCD: 4795L21 antisense siNA AAAcuGcccuuuGAGGuAGTT B 780 (4777C) stab19 645 UUCUGAUCAUUGCCAACACAAUG 589 37116 SCD: 665L21 anti sense siNA UUGUGUUGGCAAUGAUCAGTT B 781 (647C) stab22 1192 CACCACAUUCUUCAUUGAUUGCA 590 37117 SCD: 1212L21 antisense siNA CAAUCAAUGAAGAAUGUGGTT B 782 (1194C) stab22 2023 GUUUGGCAAUGCUAAUUCAAUGC 591 37118 SCD: 2043L21 antisense siNA AUUGAAUUAGCAUUGCCAATT B 783 (20250) stab22 2728 AGGCUUCUCUCCACAGUGUUGUG 592 37119 SCD: 2748L21 antisense siNA CAACACUGUGGAGAGAAGCTT B 784 (2730C) stab22 3554 ACUAACCAGCAUUCCCUACAGCC 593 37120 SCD: 3574L21 antisense siNA CUGUAGGGAAUGCUGGUUATT B 785 (3556C) stab22 4316 CUUUGCACCUGAGACCCUACUGA 594 37121 SCD: 4336L21 antisense siNA AGUAGGGUCUCAGGUGCAATT B 786 (4318C) stab22 4318 UUGCACCUGAGACCCUACUGAAG 595 37122 SCD: 4338L21 antisense siNA UCAGUAGGGUCUCAGGUGCTT B 787 (4320C) stab22 4775 ACCUACCUCAAAGGGCAGUUUUG 596 37123 SCD: 4795L21 antisense siNA AAACUGCCCUUUGAGGUAGTT B 788 (4777C) stab22 Uppercase = ribonucleotide u, c = 2′-deoxy-2′-fluoro U, C T = thymidine B = inverted deoxy abasic s = phosphorothioate linkage A = deoxy Adenosine G = deoxy Guanosine G = 2′-C-methyl Guanosine A = 2′-C-methyl Adenosine

TABLE IV Non-limiting examples of Stabilization Chemistries for chemically modified siNA constructs Chem- Pu- istry pyrimidine rine cap p = S Strand “Stab Ribo Ribo TT at 3′- S/AS 00” ends “Stab Ribo Ribo — 5 at 5′-end S/AS 1” 1 at 3′-end “Stab Ribo Ribo — All linkages Usually AS 2” “Stab 2′-fluoro Ribo — 4 at 5′-end Usually S 3” 4 at 3′-end “Stab 2′-fluoro Ribo 5′ and 3′- — Usually S 4” ends “Stab 2′-fluoro Ribo — 1 at 3′-end Usually AS 5” “Stab 2′-O-Methyl Ribo 5′ and 3′- — Usually S 6” ends “Stab 2′-fluoro 2′- 5′ and 3′- — Usually S 7” deoxy ends “Stab 2′-fluoro 2′-O- — 1 at 3′-end S/AS 8” Methyl “Stab Ribo Ribo 5′ and 3′- — Usually S 9” ends “Stab Ribo Ribo — 1 at 3′-end Usually AS 10” “Stab 2′-fluoro 2′- — 1 at 3′-end Usually AS 11” deoxy “Stab 2′-fluoro LNA 5′ and 3′- Usually S 12” ends “Stab 2′-fluoro LNA 1 at 3′-end Usually AS 13” “Stab 2′-fluoro 2′- 2 at 5′-end Usually AS 14” deoxy 1 at 3′-end “Stab 2′-deoxy 2′- 2 at 5′-end Usually AS 15” deoxy 1 at 3′-end “Stab Ribo 2′-O- 5′ and 3′- Usually S 16” Methyl ends “Stab 2′-O-Methyl 2′-O- 5′ and 3′- Usually S 17” Methyl ends “Stab 2′-fluoro 2′-O- 5′ and 3′- Usually S 18” Methyl ends “Stab 2′-fluoro 2′-O- 3′-end S/AS 19” Methyl “Stab 2′-fluoro 2′- 3′-end Usually AS 20” deoxy “Stab 2′-fluoro Ribo 3′-end Usually AS 21” “Stab Ribo Ribo 3′-end Usually AS 22” “Stab 2′-fluoro* 2′- 5′ and 3′- Usually S 23” deoxy* ends “Stab 2′-fluoro* 2′-O- — 1 at 3′-end S/AS 24” Methyl* “Stab 2′-fluoro* 2′-O- — 1 at 3′-end S/AS 25” Methyl* “Stab 2′-fluoro* 2′-O- — S/AS 26” Methyl* “Stab 2′-fluoro* 2′-O- 3′-end S/AS 27” Methyl* “Stab 2′-fluoro* 2′-O- 3′-end S/AS 28” Methyl* “Stab 2′-fluoro* 2′-O- 1 at 3′-end S/AS 29” Methyl* “Stab 2′-fluoro* 2′-O- S/AS 30” Methyl* “Stab 2′-fluoro* 2′-O- 3′-end S/AS 31” Methyl* “Stab 2′-fluoro 2′-O- S/AS 32” Methyl CAP = any terminal cap, see for example FIG. 10. All Stab 00-32 chemistries can comprise 3′-terminal thymidine (TT) residues All Stab 00-32 chemistries typically comprise about 21 nucleotides, but can vary as described herein. S = sense strand AS = antisense strand *Stab 23 has a single ribonucleotide adjacent to 3′-CAP *Stab 24 and Stab 28 have a single ribonucleotide at 5′-terminus *Stab 25, Stab 26, and Stab 27 have three ribonucleotides at 5′-terminus *Stab 29, Stab 30, and Stab 31, any purine at first three nucleotide positions from 5′-terminus are ribonucleotides p = phosphorothioate linkage

TABLE V A. 2.5 μmol Synthesis Cycle ABI 394 Instrument Reagent Equivalents Amount Wait Time* DNA Wait Time* 2′-O-methyl Wait Time*RNA Phosphoramidites 6.5 163 μL 45 sec 2.5 min 7.5 min S-Ethyl Tetrazole 23.8 238 μL 45 sec 2.5 min 7.5 min Acetic Anhydride 100 233 μL 5 sec 5 sec 5 sec N-Methyl 186 233 μL 5 sec 5 sec 5 sec Imidazole TCA 176 2.3 mL 21 sec 21 sec 21 sec Iodine 11.2 1.7 mL 45 sec 45 sec 45 sec Beaucage 12.9 645 μL 100 sec 300 sec 300 sec Acetonitrile NA 6.67 mL NA NA NA B. 0.2 μmol Synthesis Cycle ABI 394 Instrument Reagent Equivalents Amount Wait Time* DNA Wait Time* 2′-O-methyl Wait Time*RNA Phosphoramidites 15 31 μL 45 sec 233 sec 465 sec S-Ethyl Tetrazole 38.7 31 μL 45 sec 233 min 465 sec Acetic Anhydride 655 124 μL 5 sec 5 sec 5 sec N-Methyl 1245 124 μL 5 sec 5 sec 5 sec Imidazole TCA 700 732 μL 10 sec 10 sec 10 sec Iodine 20.6 244 μL 15 sec 15 sec 15 sec Beaucage 7.7 232 μL 100 sec 300 sec 300 sec Acetonitrile NA 2.64 mL NA NA NA C. 0.2 μmol Synthesis Cycle 96 well Instrument Equivalents: DNA/ Amount: DNA/2′-O- Wait Time* 2′-O- Reagent 2′-O-methyl/Ribo methyl/Ribo Wait Time* DNA methyl Wait Time* Ribo Phosphoramidites 22/33/66 40/60/120 μL 60 sec 180 sec 360 sec S-Ethyl Tetrazole  70/105/210 40/60/120 μL 60 sec 180 min 360 sec Acetic Anhydride 265/265/265 50/50/50 μL 10 sec 10 sec 10 sec N-Methyl 502/502/502 50/50/50 μL 10 sec 10 sec 10 sec Imidazole TCA 238/475/475 250/500/500 μL 15 sec 15 sec 15 sec Iodine 6.8/6.8/6.8 80/80/80 μL 30 sec 30 sec 30 sec Beaucage 34/51/51 80/120/120 100 sec 200 sec 200 sec Acetonitrile NA 1150/1150/1150 μL NA NA NA Wait time does not include contact time during delivery. Tandem synthesis utilizes double coupling of linker molecule 

1. A chemically modified nucleic acid molecule, wherein: (a) the nucleic acid molecule comprises a sense strand and a separate antisense strand, each strand having one or more pyrimidine nucleotides and one or more purine nucleotides; (b) each strand of the nucleic acid molecule is independently 18 to 27 nucleotides in length; (c) an 18 to 27 nucleotide sequence of the antisense strand is complementary to a human Stearoyl-CoA Desaturase (SCD) RNA sequence comprising SEQ ID NO:811; (d) an 18 to 27 nucleotide sequence of the sense strand is complementary to the antisense strand and comprises an 18 to 27 nucleotide sequence of the human RNA sequence; and (e) 50 percent or more of the nucleotides in each strand comprise a 2′-sugar modification, wherein the 2′-sugar modification of any of the pyrimidine nucleotides differs from the 2′-sugar modification of any of the purine nucleotides.
 2. The nucleic acid molecule of claim 1, wherein the 2′-sugar modification of any of the purine nucleotides in the sense strand differs from the 2′-sugar modification of any of the purine nucleotides in the antisense strand.
 3. The nucleic acid molecule of claim 1, wherein the 2′-sugar modification is selected from the group consisting of 2′-deoxy-2′-fluoro, 2′-O-methyl, and 2′-deoxy.
 4. The nucleic acid of claim 3, wherein the 2′-deoxy-2′-fluoro sugar modification is a pyrimidine modification.
 5. The nucleic acid of claim 3, wherein the 2′-deoxy sugar modification is a pyrimidine modification.
 6. The nucleic acid of claim 3, wherein the 2′-O-methyl sugar modification is a pyrimidine modification.
 7. The nucleic acid molecule of claim 4, wherein said pyrimidine modification is in the sense strand, the antisense strand, or both the sense strand and antisense strand.
 8. The nucleic acid molecule of claim 6, wherein said pyrimidine modification is in the sense strand, the antisense strand, or both the sense strand and antisense strand.
 9. The nucleic acid molecule of claim 3, wherein the 2′-deoxy sugar modification is a purine modification.
 10. The nucleic acid molecule of claim 3, wherein the 2′-O-methyl sugar modification is a purine modification.
 11. The nucleic acid molecule of claim 9, wherein the purine modification is in the sense strand.
 12. The nucleic acid molecule of claim 10, wherein the purine modification is in the antisense strand.
 13. The nucleic acid molecule of claim 1, wherein the nucleic acid molecule comprises ribonucleotides.
 14. The nucleic acid molecule of claim 1, wherein the sense strand includes a terminal cap moiety at the 5′-end, the 3′-end, or both of the 5′- and 3′-ends.
 15. The nucleic acid molecule of claim 14, wherein the terminal cap moiety is an inverted deoxy abasic moiety.
 16. The nucleic acid molecule of claim 1, wherein said nucleic acid molecule includes one or more phosphorothioate internucleotide linkages.
 17. The nucleic acid molecule of claim 16, wherein one of the phosphorothioate internucleotide linkages is at the 3′-end of the antisense strand.
 18. The nucleic acid molecule of claim 1, wherein the 5′-end of the antisense strand includes a terminal phosphate group.
 19. The nucleic acid molecule of claim 1, wherein the sense strand, the antisense strand, or both the sense strand and the antisense strand include a 3′-overhang.
 20. A composition comprising the nucleic acid molecule of claim 1, in a pharmaceutically acceptable carrier or diluent. 